Polycarbonate polyol compositions and methods

ABSTRACT

In one aspect, the present disclosure encompasses polymerization systems for the copolymerization of CO 2  and epoxides comprising 1) a catalyst including a metal coordination compound having a permanent ligand set and at least one ligand that is a polymerization initiator, and 2) a chain transfer agent having two or more sites that can initiate polymerization. In a second aspect, the present disclosure encompasses methods for the synthesis of polycarbonate polyols using the inventive polymerization systems. In a third aspect, the present disclosure encompasses polycarbonate polyol compositions characterized in that the polymer chains have a high percentage of —OH end groups and a high percentage of carbonate linkages. The compositions are further characterized in that they contain polymer chains having an embedded polyfunctional moiety linked to a plurality of individual polycarbonate chains.

PRIORITY CLAIM

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/095,178, filed Sep. 8, 2008, the entire contents of whichare incorporated herein by reference.

BACKGROUND

Aliphatic polycarbonates (APCs) have utility as polyol building blocksfor the construction of co-polymers such as flexible urethane foams,urethane coatings, rigid urethane foams, urethane/urea elastomers andplastics, adhesives, polymeric coatings and surfactants among others.Examples of such APCs include polypropylene carbonate) (PPC);poly(ethylene carbonate) (PEC); poly(butylene carbonate) (PBC); andpoly(cyclohexene carbonate) (PCHC) as well as copolymers of two or moreof these.

To have utility in these applications, it is preferable that allpolycarbonate polymer chain ends terminate with hydroxyl groups. Suchhydroxyl groups serve as reactive moieties for cross-linking reactionsor act as sites on which other blocks of a co-polymer can beconstructed. It is problematic if a portion of the chain ends on the APCare not hydroxy groups since this results in incomplete cross-linking ortermination of the block copolymer. A typical specification foraliphatic polycarbonate polyol resins for use in such applications isthat at least 98% or in some cases greater than 99% of chain endsterminate in hydroxyl groups. In addition, these applications typicallycall for relatively low molecular weight oligomers (e.g. polymers havingaverage molecular weight numbers (M_(n)) between about 500 and about15,000 g/mol). It is also desirable that the polyols have a narrowlydefined molecular weight distribution—for example, a polydispersityindex less than about 2 is desirable, but much narrower distributions(i.e. PDI<1.2) can be advantageous. Furthermore, for certainapplications, polyol polycarbonates having little or no contaminationwith ether linkages are desirable.

Aliphatic polycarbonates can be conveniently synthesized bycopolymerization of carbon dioxide and epoxides as shown in Scheme 1.

Currently, there are several catalytic systems utilized for suchsyntheses, namely: heterogeneous catalyst systems based on zinc oraluminum salts; double metal cyanide (DMC) catalysts; and homogenouscatalysts based on coordination complexes of transition metals oraluminum.

The catalytic systems using heterogeneous zinc or aluminum salts aretypified by those first described by Inoue in the 1960s (for example inU.S. Pat. Nos. 3,900,424 and 3,953,383. Further improvements to thesecatalysts have been made over the years (for example as described in W.Kuran, et al. Chem. Macromol. Chem. Phys. 1976, 177, pp 11-20 andGorecki, et al. J. Polym. Sci. Part C 1985, 23, pp. 299-304).Nonetheless, these catalyst systems are generally not suitable forproducing polyol resins with the low molecular weights and narrowpolydispersity demanded by many applications. The catalysts are ofrelatively low activity and produce high molecular weight polymer withbroad polydispersity. Additionally, the polycarbonates produced by thesecatalysts have a significant proportion of ether linkages in the chainwhich can be undesirable in certain applications.

A second class of catalysts for the polymerization of epoxides and CO₂are the double metal cyanide (DMC) catalysts. Such catalysts areexemplified by those reported by Kruper and Smart in U.S. Pat. No.4,500,704. Compared to the Inoue-type catalysts, the DMC systems arebetter suited to the formation of low molecular weight polymers andproduce a predominance of chains with hydroxyl end groups. However,these catalysts produce polymers having a high proportion of etherlinkages and the materials they produce are more properly regarded aspolycarbonate-polyether copolymers rather than as aliphaticpolycarbonates per se.

A more recently developed class of catalysts is based on coordinationcomplexes of aluminum or a variety of transition metals, particularlycomplexes of cobalt, chromium and manganese. Examples of such catalystsare disclosed in U.S. Pat. Nos. 6,870,004 and 7,304,172. In some casesthese catalytic systems are highly active and are capable of providingaliphatic polycarbonate with narrow polydispersity, a high percentage ofcarbonate linkages and good regioselectivity (e.g. high head-to-tailratios for incorporation of monosubstituted epoxides). However, at highconversions under standard conditions, these catalysts produce highmolecular weight polymers that are not suitable for many polyolapplications. Additionally, using these systems, it has not beenpractical to synthesize polycarbonate polyols having a high percentageof hydroxyl end-groups.

The lack of hydroxyl end-groups is due to the fact that anion(s)associated with the metal center of the catalyst complex becomecovalently bound to the polymer chain during initiation of polymer chaingrowth. This is true also of anions associated with any optionallypresent cationic co-catalysts used in these reactions. Without wishingto be bound by theory or thereby limit the scope of the presentinvention, the sequence shown in Scheme 2, depicts a probable reactionsequence showing why the anions (denoted —X) associated with thecatalyst complex

become covalently linked to the polycarbonate chain.

The counterions —X typically used for these catalysts include halides,sulfonates, phenolates, carboxylates and azide. Because polymerizationis initiated when one of these anions opens an epoxide ring, one end ofeach polymer chain (the initiation end) is necessarily capped with anon-hydroxyl moiety such as a halogen, an alkylsulfonate, a phenylether,an acyl group, or an azide, respectively.

The other factor disfavoring the use of these catalytic systems toproduce polyol resins is the fact that they produce high molecularweight polymer when taken to high conversions. Typical molecular weightsare in the range of 20,000 to 400,000 g/mol—values well above themolecular weight range desired for most polyol resin applications.Potential strategies to produce lower molecular weight materialsinclude: stopping the polymerization at low conversion; using highcatalyst concentrations; degrading the high molecular weight polymer toshorter chains, or using chain transfer agents (CTAs) such as alcoholsduring the polymerization. Stopping the reaction at low conversion orincreasing the catalyst concentration are undesirable due to costconsiderations and added difficulties in purification occasioned by theincreased concentration of catalyst-derived contaminants in the crudepolymer. Degradation of higher molecular weight polymers to produce lowmolecular weight resins leads to increased polydispersity, addsadditional steps to the production process, and leads to contaminationwith cyclic by-products. Chain transfer agents can be successfullyemployed to lower the molecular weight of the polymer without asignificant increase in cost or contamination. However, this strategydoes not alleviate the problem of non-hydroxyl end groups since polymerchains initiated by chain transfer agent will still have one end cappedwith a non-hydroxyl moiety (i.e. an ether corresponding to the alcoholused as the CTA).

As such, there remains a need for catalysts and methods that are capableof efficiently producing polycarbonate polyols having high carbonatecontent.

SUMMARY OF THE INVENTION

In one aspect, the present disclosure encompasses polymerization systemsfor the copolymerization of CO₂ and epoxides comprising 1) a metalcomplex including a metal coordination compound having a permanentligand set and at least one ligand that is a polymerization initiator,and 2) a chain transfer agent having two or more sites that can initiatepolymerization.

In some embodiments, a ligand that is a polymerization initiator has twoor more sites capable of initiating polymerization, this variation leadsto polycarbonate polyols with an extremely high proportion of —OH endgroups. In certain embodiments, the chain transfer agent and the ligandthat is a polymerization initiator are the same molecule (or ionic formsof the same molecule).

In certain embodiments, a polymerization system further includes aco-catalyst. In some embodiments, the co-catalyst is a cationic organicmolecule. In certain embodiments, an anion present to balance the chargeof a cationic co-catalyst is also a polymerization initiator having twoor more sites that can initiate polymerization. In certain embodiments,the ligand that is a polymerization initiator, and the counterion of theco-catalyst are the same molecule. In certain embodiments, the chaintransfer agent, the ligand that is a polymerization initiator, and ananion associated with a co-catalyst are the same molecule (or ionicforms of the same molecule).

In some embodiments, the present disclosure encompasses methods for thesynthesis of polycarbonate polyols. In some embodiments, a methodincludes the steps of: 1) providing a reaction mixture including one ormore epoxides and at least one chain transfer agent having two or moresites capable of initiating polymerization, 2) contacting the reactionmixture with a with a metal complex comprising a metal coordinationcompound having a permanent ligand set and at least one ligand that is apolymerization initiator, and 3) allowing the polymerization reaction toproceed for a length of time sufficient for the average molecular weightof the polycarbonate polyol formed to reach a desired value. In someembodiments the method further includes contacting the reaction mixturewith a co-catalyst.

In some embodiments, the present disclosure encompasses polycarbonatepolyol compositions characterized in that polymer chains have a highpercentage of —OH end groups and a high percentage of carbonatelinkages. Such compositions are further characterized in that polymerchains contain within them a polyfunctional moiety linked to a pluralityof individual polycarbonate chains. In certain embodiments,polycarbonate polyol compositions are further characterized by havingone or more of the following features: a carbonate-to-ether linkageratio of at least 10:1, a head-to-tail ratio of at least 5:1, or apolydispersity index of less than 2. In certain embodiments of thisaspect, a polymer composition is further characterized in that a polymercontains a plurality of polymer chain types differentiated by thepresence of different polyfunctional polymerization initiators embeddedwithin the chain, or by differences in the end-groups present on thepolymer chains.

In certain embodiments, polycarbonate polyol compositions of the presentdisclosure are further characterized in that they contain a mixture oftwo or more chain types, wherein the chain different chain types aredifferentiated from one another by differences in the identity of theembedded polyfunctional polymerization initiators, the absence ofembedded polyfunctional polymerization initiators, or the presence ofnon-hydroxyl end groups on certain chains.

DEFINITIONS

Definitions of specific functional groups and chemical terms aredescribed in more detail below. For purposes of this invention, thechemical elements are identified in accordance with the Periodic Tableof the Elements, CAS version, Handbook of Chemistry and Physics, 75^(th)Ed., inside cover, and specific functional groups are generally definedas described therein. Additionally, general principles of organicchemistry, as well as specific functional moieties and reactivity, aredescribed in Organic Chemistry, Thomas Sorrell, University ScienceBooks, Sausalito, 1999; Smith and March March's Advanced OrganicChemistry, 5^(th) Edition, John Wiley & Sons, Inc., New York, 2001;Larock, Comprehensive Organic Transformations, VCH Publishers, Inc., NewYork, 1989; Carruthers, Some Modern Methods of Organic Synthesis, 3^(rd)Edition, Cambridge University Press, Cambridge, 1987; the entirecontents of each of which are incorporated herein by reference.

Certain compounds of the present invention can comprise one or moreasymmetric centers, and thus can exist in various stereoisomeric forms,e.g., enantiomers and/or diastereomers. Thus, inventive compounds andcompositions thereof may be in the form of an individual enantiomer,diastereomer or geometric isomer, or may be in the form of a mixture ofstereoisomers. In certain embodiments, the compounds of the inventionare enantiopure compounds. In certain other embodiments, mixtures ofenantiomers or diastereomers are provided.

Furthermore, certain compounds, as described herein may have one or moredouble bonds that can exist as either the Z or E isomer, unlessotherwise indicated. The invention additionally encompasses thecompounds as individual isomers substantially free of other isomers andalternatively, as mixtures of various isomers, e.g., racemic mixtures ofenantiomers. In addition to the above-mentioned compounds per se, thisinvention also encompasses compositions comprising one or morecompounds.

As used herein, the term “isomers” includes any and all geometricisomers and stereoisomers. For example, “isomers” include cis- andtrans-isomers, E- and Z-isomers, R- and S-enantiomers, diastereomers,(D)-isomers, (L)-isomers, racemic mixtures thereof, and other mixturesthereof, as falling within the scope of the invention. For instance, astereoisomer may, in some embodiments, be provided substantially free ofone or more corresponding stereoisomers, and may also be referred to as“stereochemically enriched.”

Where a particular enantiomer is preferred, it may, in some embodimentsbe provided substantially free of the opposite enantiomer, and may alsobe referred to as “optically enriched.” “Optically enriched,” as usedherein, means that the compound is made up of a significantly greaterproportion of one enantiomer. In certain embodiments the compound ismade up of at least about 90% by weight of a preferred enantiomer. Inother embodiments the compound is made up of at least about 95%, 98%, or99% by weight of a preferred enantiomer. Preferred enantiomers may beisolated from racemic mixtures by any method known to those skilled inthe art, including chiral high pressure liquid chromatography (HPLC) andthe formation and crystallization of chiral salts or prepared byasymmetric syntheses. See, for example, Jacques, et al., Enantiomers,Racemates and Resolutions (Wiley Interscience, New York, 1981); Wilen,S. H., et al., Tetrahedron 33:2725 (1977); Eliel, E. L. Stereochemistryof Carbon Compounds (McGraw-Hill, NY, 1962); Wilen, S. H. Tables ofResolving Agents and Optical Resolutions p. 268 (E. L. Eliel, Ed., Univ.of Notre Dame Press, Notre Dame, Ind. 1972).

The terms “halo” and “halogen” as used herein refer to an atom selectedfrom fluorine (fluoro, —F), chlorine (chloro, —Cl), bromine (bromo,—Br), and iodine (iodo, —I).

The term “aliphatic” or “aliphatic group”, as used herein, denotes ahydrocarbon moiety that may be straight-chain (i.e., unbranched),branched, or cyclic (including fused, bridging, and spiro-fusedpolycyclic) and may be completely saturated or may contain one or moreunits of unsaturation, but which is not aromatic. Unless otherwisespecified, aliphatic groups contain 1-30 carbon atoms. In certainembodiments, aliphatic groups contain 1-12 carbon atoms. In certainembodiments, aliphatic groups contain 1-8 carbon atoms. In certainembodiments, aliphatic groups contain 1-6 carbon atoms. In someembodiments, aliphatic groups contain 1-5 carbon atoms, in someembodiments, aliphatic groups contain 1-4 carbon atoms, in yet otherembodiments aliphatic groups contain 1-3 carbon atoms, and in yet otherembodiments aliphatic groups contain 1 or 2 carbon atoms. Suitablealiphatic groups include, but are not limited to, linear or branched,alkyl, alkenyl, and alkynyl groups, and hybrids thereof such as(cycloalkyl)alkyl, (cycloalkenyl)alkyl or (cycloalkyl)alkenyl.

The term “unsaturated”, as used herein, means that a moiety has one ormore double or triple bonds.

The terms “cycloaliphatic”, “carbocycle”, or “carbocyclic”, used aloneor as part of a larger moiety, refer to a saturated or partiallyunsaturated cyclic aliphatic monocyclic or polycyclic ring systems, asdescribed herein, having from 3 to 12 members, wherein the aliphaticring system is optionally substituted as defined above and describedherein. Cycloaliphatic groups include, without limitation, cyclopropyl,cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl,cycloheptyl, cycloheptenyl, cyclooctyl, cyclooctenyl, norbornyl,adamantyl, and cyclooctadienyl. In some embodiments, the cycloalkyl has3-6 carbons. The terms “cycloaliphatic”, “carbocycle” or “carbocyclic”also include aliphatic rings that are fused to one or more aromatic ornonaromatic rings, such as decahydronaphthyl or tetrahydronaphthyl,where the radical or point of attachment is on the aliphatic ring. Incertain embodiments, the term “3- to 8-membered carbocycle” refers to a3- to 8-membered saturated or partially unsaturated monocycliccarbocyclic ring. In certain embodiments, the terms “3- to 14-memberedcarbocycle” and “C₃₋₁₄ carbocycle” refer to a 3- to 8-membered saturatedor partially unsaturated monocyclic carbocyclic ring, or a 7- to14-membered saturated or partially unsaturated polycyclic carbocyclicring. In certain embodiments, the term “C₃₋₂₀ carbocycle” refers to a 3-to 8-membered saturated or partially unsaturated monocyclic carbocyclicring, or a 7- to 20-membered saturated or partially unsaturatedpolycyclic carbocyclic ring.

The term “alkyl,” as used herein, refers to saturated, straight- orbranched-chain hydrocarbon radicals derived from an aliphatic moietycontaining between one and six carbon atoms by removal of a singlehydrogen atom. Unless otherwise specified, alkyl groups contain 1-12carbon atoms. In certain embodiments, alkyl groups contain 1-8 carbonatoms. In certain embodiments, alkyl groups contain 1-6 carbon atoms. Insome embodiments, alkyl groups contain 1-5 carbon atoms, in someembodiments, alkyl groups contain 1-4 carbon atoms, in yet otherembodiments alkyl groups contain 1-3 carbon atoms, and in yet otherembodiments alkyl groups contain 1-2 carbon atoms. Examples of alkylradicals include, but are not limited to, methyl, ethyl, n-propyl,isopropyl, n-butyl, iso-butyl, sec-butyl, sec-pentyl, iso-pentyl,tert-butyl, n-pentyl, neopentyl, n-hexyl, sec-hexyl, n-heptyl, n-octyl,n-decyl, n-undecyl, dodecyl, and the like.

The term “alkenyl,” as used herein, denotes a monovalent group derivedfrom a straight- or branched-chain aliphatic moiety having at least onecarbon-carbon double bond by the removal of a single hydrogen atom.Unless otherwise specified, alkenyl groups contain 2-12 carbon atoms. Incertain embodiments, alkenyl groups contain 2-8 carbon atoms. In certainembodiments, alkenyl groups contain 2-6 carbon atoms. In someembodiments, alkenyl groups contain 2-5 carbon atoms, in someembodiments, alkenyl groups contain 2-4 carbon atoms, in yet otherembodiments alkenyl groups contain 2-3 carbon atoms, and in yet otherembodiments alkenyl groups contain 2 carbon atoms. Alkenyl groupsinclude, for example, ethenyl, propenyl, butenyl, 1-methyl-2-buten-1-yl,and the like.

The term “alkynyl,” as used herein, refers to a monovalent group derivedfrom a straight- or branched-chain aliphatic moiety having at least onecarbon-carbon triple bond by the removal of a single hydrogen atom.Unless otherwise specified, alkynyl groups contain 2-12 carbon atoms. Incertain embodiments, alkynyl groups contain 2-8 carbon atoms. In certainembodiments, alkynyl groups contain 2-6 carbon atoms. In someembodiments, alkynyl groups contain 2-5 carbon atoms, in someembodiments, alkynyl groups contain 2-4 carbon atoms, in yet otherembodiments alkynyl groups contain 2-3 carbon atoms, and in yet otherembodiments alkynyl groups contain 2 carbon atoms. Representativealkynyl groups include, but are not limited to, ethynyl, 2-propynyl(propargyl), 1-propynyl, and the like.

The term “aryl” used alone or as part of a larger moiety as in“aralkyl”, “aralkoxy”, or “aryloxyalkyl”, refers to monocyclic andpolycyclic ring systems having a total of five to 20 ring members,wherein at least one ring in the system is aromatic and wherein eachring in the system contains three to twelve ring members. The term“aryl” may be used interchangeably with the term “aryl ring”. In certainembodiments of the present invention, “aryl” refers to an aromatic ringsystem which includes, but is not limited to, phenyl, biphenyl,naphthyl, anthracyl and the like, which may bear one or moresubstituents. Also included within the scope of the term “aryl”, as itis used herein, is a group in which an aromatic ring is fused to one ormore additional rings, such as benzofuranyl, indanyl, phthalimidyl,naphthimidyl, phenantriidinyl, or tetrahydronaphthyl, and the like. Incertain embodiments, the terms “6- to 10-membered aryl” and “C₆₋₁₀ aryl”refer to a phenyl or an 8- to 10-membered polycyclic aryl ring. Incertain embodiments, the term “6- to 12-membered aryl” refers to aphenyl or an 8- to 12-membered polycyclic aryl ring. In certainembodiments, the term “C₆₋₁₄ aryl” refers to a phenyl or an 8- to14-membered polycyclic aryl ring.

The terms “heteroaryl” and “heteroar-”, used alone or as part of alarger moiety, e.g., “heteroaralkyl”, or “heteroaralkoxy”, refer togroups having 5 to 14 ring atoms, preferably 5, 6, or 9 ring atoms;having 6, 10, or 14π electrons shared in a cyclic array; and having, inaddition to carbon atoms, from one to five heteroatoms. The term“heteroatom” refers to nitrogen, oxygen, or sulfur, and includes anyoxidized form of nitrogen or sulfur, and any quaternized form of a basicnitrogen. Heteroaryl groups include, without limitation, thienyl,furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl,oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl,thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl,purinyl, naphthyridinyl, benzofuranyl and pteridinyl. The terms“heteroaryl” and “heteroar-”, as used herein, also include groups inwhich a heteroaromatic ring is fused to one or more aryl,cycloaliphatic, or heterocyclyl rings, where the radical or point ofattachment is on the heteroaromatic ring. Nonlimiting examples includeindolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl,indazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl,cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl,carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl,tetrahydroquinolinyl, tetrahydroisoquinolinyl, andpyrido[2,3-b]-1,4-oxazin-3(4H)-one. A heteroaryl group may be mono- orbicyclic. The term “heteroaryl” may be used interchangeably with theterms “heteroaryl ring”, “heteroaryl group”, or “heteroaromatic”, any ofwhich terms include rings that are optionally substituted. The term“heteroaralkyl” refers to an alkyl group substituted by a heteroaryl,wherein the alkyl and heteroaryl portions independently are optionallysubstituted. In certain embodiments, the term “5- to 10-memberedheteroaryl” refers to a 5- to 6-membered heteroaryl ring having 1 to 3heteroatoms independently selected from nitrogen, oxygen, or sulfur, oran 8- to 10-membered bicyclic heteroaryl ring having 1 to 4 heteroatomsindependently selected from nitrogen, oxygen, or sulfur. In certainembodiments, the term “5- to 12-membered heteroaryl” refers to a 5- to6-membered heteroaryl ring having 1 to 3 heteroatoms independentlyselected from nitrogen, oxygen, or sulfur, or an 8- to 12-memberedbicyclic heteroaryl ring having 1 to 4 heteroatoms independentlyselected from nitrogen, oxygen, or sulfur.

As used herein, the terms “heterocycle”, “heterocyclyl”, “heterocyclicradical”, and “heterocyclic ring” are used interchangeably and refer toa stable 5- to 7-membered monocyclic or 7-14-membered polycyclicheterocyclic moiety that is either saturated or partially unsaturated,and having, in addition to carbon atoms, one or more, preferably one tofour, heteroatoms, as defined above. When used in reference to a ringatom of a heterocycle, the term “nitrogen” includes a substitutednitrogen. As an example, in a saturated or partially unsaturated ringhaving 0-3 heteroatoms selected from oxygen, sulfur or nitrogen, thenitrogen may be N (as in 3,4-dihydro-2H-pyrrolyl), NH (as inpyrrolidinyl), or ⁻NR (as in N-substituted pyrrolidinyl). In someembodiments, the term “3- to 7-membered heterocyclic” refers to a 3- to7-membered saturated or partially unsaturated monocyclic heterocyclicring having 1 to 2 heteroatoms independently selected from nitrogen,oxygen, or sulfur. In some embodiments, the term “3- to 8-memberedheterocycle” refers to a 3- to 8-membered saturated or partiallyunsaturated monocyclic heterocyclic ring having 1 to 2 heteroatomsindependently selected from nitrogen, oxygen, or sulfur. In someembodiments, the term “3- to 12-membered heterocyclic” refers to a 3- to8-membered saturated or partially unsaturated monocyclic heterocyclicring having 1 to 2 heteroatoms independently selected from nitrogen,oxygen, or sulfur, or a 7- to 12-membered saturated or partiallyunsaturated polycyclic heterocyclic ring having 1-3 heteroatomsindependently selected from nitrogen, oxygen, or sulfur. In someembodiments, the term “3- to 14-membered heterocycle” refers to a 3- to8-membered saturated or partially unsaturated monocyclic heterocyclicring having 1 to 2 heteroatoms independently selected from nitrogen,oxygen, or sulfur, or a 7- to 14-membered saturated or partiallyunsaturated polycyclic heterocyclic ring having 1-3 heteroatomsindependently selected from nitrogen, oxygen, or sulfur.

A heterocyclic ring can be attached to its pendant group at anyheteroatom or carbon atom that results in a stable structure and any ofthe ring atoms can be optionally substituted. Examples of such saturatedor partially unsaturated heterocyclic radicals include, withoutlimitation, tetrahydrofuranyl, tetrahydrothienyl, pyrrolidinyl,pyrrolidonyl, piperidinyl, pyrrolinyl, tetrahydroquinolinyl,tetrahydroisoquinolinyl, decahydroquinolinyl, oxazolidinyl, piperazinyl,dioxanyl, dioxolanyl, diazepinyl, oxazepinyl, thiazepinyl, morpholinyl,and quinuclidinyl. The terms “heterocycle”, “heterocyclyl”,“heterocyclyl ring”, “heterocyclic group”, “heterocyclic moiety”, and“heterocyclic radical”, are used interchangeably herein, and alsoinclude groups in which a heterocyclyl ring is fused to one or morearyl, heteroaryl, or cycloaliphatic rings, such as indolinyl,3H-indolyl, chromanyl, phenanthridinyl, or tetrahydroquinolinyl, wherethe radical or point of attachment is on the heterocyclyl ring. Aheterocyclyl group may be mono- or bicyclic. The term“heterocyclylalkyl” refers to an alkyl group substituted by aheterocyclyl, wherein the alkyl and heterocyclyl portions independentlyare optionally substituted.

As used herein, the term “partially unsaturated” refers to a ring moietythat includes at least one double or triple bond. The term “partiallyunsaturated” is intended to encompass rings having multiple sites ofunsaturation, but is not intended to include aryl or heteroarylmoieties, as herein defined.

One of ordinary skill in the art will appreciate that compound andsynthetic methods, as described herein, may utilize a variety ofprotecting groups. By the term “protecting group,” as used herein, it ismeant that a particular functional moiety, e.g., O, S, or N, is maskedor blocked, permitting, if desired, a reaction to be carried outselectively at another reactive site in a multifunctional compound.Suitable protecting groups are well known in the art and include thosedescribed in detail in Protecting Groups in Organic Synthesis, T. W.Greene and P. G. M. Wuts, 3^(rd) edition, John Wiley & Sons, 1999, theentirety of which is incorporated herein by reference. In certainembodiments, a protecting group reacts selectively in good yield to givea protected substrate that is stable to the projected reactions; theprotecting group is preferably selectively removable by readilyavailable, preferably non-toxic reagents that do not attack the otherfunctional groups; the protecting group forms a separable derivative(more preferably without the generation of new stereogenic centers); andthe protecting group will preferably have a minimum of additionalfunctionality to avoid further sites of reaction. As detailed herein,oxygen, sulfur, nitrogen, and carbon protecting groups may be utilized.By way of non-limiting example, hydroxyl protecting groups includemethyl, methoxylmethyl (MOM), methylthiomethyl (MTM), t-butylthiomethyl,(phenyldimethylsilyl)methoxymethyl (SMOM), benzyloxymethyl (BOM),p-methoxybenzyloxymethyl (PMBM), (4-methoxyphenoxy)methyl (p-AOM),guaiacolmethyl (GUM), t-butoxymethyl, 4-pentenyloxymethyl (POM),siloxymethyl, 2-methoxyethoxymethyl (MEM), 2,2,2-trichloroethoxymethyl,bis(2-chloroethoxy)methyl, 2-(trimethylsilyl)ethoxymethyl (SEMOR),tetrahydropyranyl (THP), 3-bromotetrahydropyranyl,tetrahydrothiopyranyl, 1-methoxycyclohexyl, 4-methoxytetrahydropyranyl(MTHP), 4-methoxytetrahydrothiopyranyl, 4-methoxytetrahydrothiopyranylS,S-dioxide, 1-[(2-chloro-4-methyl)phenyl]-4-methoxypiperidin-4-ylCTMP), 1,4-dioxan-2-yl, tetrahydrofuranyl, tetrahydrothiofuranyl,2,3,3a,4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl,1-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 1-methyl-1-methoxyethyl,1-methyl-1-benzyloxyethyl, 1-methyl-1-benzyloxy-2-fluoroethyl,2,2,2-trichloroethyl, 2-trimethylsilylethyl, 2-(phenylselenyl)ethyl,t-butyl, allyl, p-chlorophenyl, p-methoxyphenyl, 2,4-dinitrophenyl,benzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, o-nitrobenzyl,p-nitrobenzyl, p-halobenzyl, 2,6-dichlorobenzyl, p-cyanobenzyl,p-phenylbenzyl, 2-picolyl, 4-picolyl, 3-methyl-2-picolyl N-oxido,diphenylmethyl, p,p′-dinitrobenzhydryl, 5-dibenzosuberyl,triphenylmethyl, α-naphthyldiphenylmethyl,p-methoxyphenyldiphenylmethyl, di(p-methoxyphenyl)phenylmethyl,tri(p-methoxyphenyl)methyl, 4-(4′-bromophenacyloxyphenyl)diphenylmethyl,4,4′,4″-tris(4,5-dichlorophthalimidophenyl)methyl,4,4′,4″-tris(levulinoyloxyphenyl)methyl,4,4′,4″-tris(benzoyloxyphenyl)methyl,3-(imidazol-1-yl)bis(4′,4″-dimethoxyphenyl)methyl,1,1-bis(4-methoxyphenyl)-1′-pyrenylmethyl, 9-anthryl,9-(9-phenyl)xanthenyl, 9-(9-phenyl-10-oxo)anthryl,1,3-benzodithiolan-2-yl, benzisothiazolyl S,S-dioxido, trimethylsilyl(TMS), triethylsilyl (TES), triisopropylsilyl (TIPS),dimethylisopropylsilyl (IPDMS), diethylisopropylsilyl (DEIPS),dimethylthexylsilyl, t-butyldimethylsilyl (TBDMS), t-butyldiphenylsilyl(TBDPS), tribenzylsilyl, tri-p-xylylsilyl, triphenylsilyl,diphenylmethylsilyl (DPMS), t-butylmethoxyphenylsilyl (TBMPS), formate,benzoylformate, acetate, chloroacetate, dichloroacetate,trichloroacetate, trifluoroacetate, methoxyacetate,triphenylmethoxyacetate, phenoxyacetate, p-chlorophenoxyacetate,3-phenylpropionate, 4-oxopentanoate(levulinate),4,4-(ethylenedithio)pentanoate(levulinoyldithioacetal), pivaloate,adamantoate, crotonate, 4-methoxycrotonate, benzoate, p-phenylbenzoate,2,4,6-trimethylbenzoate(mesitoate), alkyl methyl carbonate,9-fluorenylmethyl carbonate (Fmoc), alkyl ethyl carbonate, alkyl2,2,2-trichloroethyl carbonate (Troc), 2-(trimethylsilyl)ethyl carbonate(TMSEC), 2-(phenylsulfonyl)ethyl carbonate (Psec),2-(triphenylphosphonio)ethyl carbonate (Peoc), alkyl isobutyl carbonate,alkyl vinyl carbonate alkyl allyl carbonate, alkyl p-nitrophenylcarbonate, alkyl benzyl carbonate, alkyl p-methoxybenzyl carbonate,alkyl 3,4-dimethoxybenzyl carbonate, alkyl o-nitrobenzyl carbonate,alkyl p-nitrobenzyl carbonate, alkyl S-benzyl thiocarbonate,4-ethoxy-1-napththyl carbonate, methyl dithiocarbonate, 2-iodobenzoate,4-azidobutyrate, 4-nitro-4-methylpentanoate, o-(dibromomethyl)benzoate,2-formylbenzenesulfonate, 2-(methylthiomethoxy)ethyl,4-(methylthiomethoxy)butyrate, 2-(methylthiomethoxymethyl)benzoate,2,6-dichloro-4-methylphenoxyacetate,2,6-dichloro-4-(1,1,3,3-tetramethylbutyl)phenoxyacetate,2,4-bis(1,1-dimethylpropyl)phenoxyacetate, chlorodiphenylacetate,isobutyrate, monosuccinoate, (E)-2-methyl-2-butenoate,o-(methoxycarbonyl)benzoate, α-naphthoate, nitrate, alkylN,N,N′,N′-tetramethylphosphorodiamidate, alkyl N-phenylcarbamate,borate, dimethylphosphinothioyl, alkyl 2,4-dinitrophenylsulfenate,sulfate, methanesulfonate (mesylate), benzylsulfonate, and tosylate(Ts). For protecting 1,2- or 1,3-diols, the protecting groups includemethylene acetal, ethylidene acetal, 1-t-butylethylidene ketal,1-phenylethylidene ketal, (4-methoxyphenyl)ethylidene acetal,2,2,2-trichloroethylidene acetal, acetonide, cyclopentylidene ketal,cyclohexylidene ketal, cycloheptylidene ketal, benzylidene acetal,p-methoxybenzylidene acetal, 2,4-dimethoxybenzylidene ketal,3,4-dimethoxybenzylidene acetal, 2-nitrobenzylidene acetal,methoxymethylene acetal, ethoxymethylene acetal, dimethoxymethyleneortho ester, 1-methoxyethylidene ortho ester, 1-ethoxyethylidine orthoester, 1,2-dimethoxyethylidene ortho ester, α-methoxybenzylidene orthoester, 1-(N,N-dimethylamino)ethylidene derivative,α-(N,N′-dimethylamino)benzylidene derivative, 2-oxacyclopentylideneortho ester, di-t-butylsilylene group (DTBS),1,3-(1,1,3,3-tetraisopropyldisiloxanylidene) derivative (TIPDS),tetra-t-butoxydisiloxane-1,3-diylidene derivative (TBDS), cycliccarbonates, cyclic boronates, ethyl boronate, and phenyl boronate.Amino-protecting groups include methyl carbamate, ethyl carbamante,9-fluorenylmethyl carbamate (Fmoc), 9-(2-sulfo)fluorenylmethylcarbamate, 9-(2,7-dibromo)fluoroenylmethyl carbamate,2,7-di-t-butyl-[9-(10,10-dioxo-10,10,10,10-tetrahydrothioxanthyl)]methylcarbamate (DBD-Tmoc), 4-methoxyphenacyl carbamate (Phenoc),2,2,2-trichloroethyl carbamate (Troc), 2-trimethylsilylethyl carbamate(Teoc), 2-phenylethyl carbamate (hZ), 1-(1-adamantyl)-1-methylethylcarbamate (Adpoc), 1,1-dimethyl-2-haloethyl carbamate,1,1-dimethyl-2,2-dibromoethyl carbamate (DB-t-BOC),1,1-dimethyl-2,2,2-trichloroethyl carbamate (TCBOC),1-methyl-1-(4-biphenylyl)ethyl carbamate (Bpoc),1-(3,5-di-t-butylphenyl)-1-methylethyl carbamate (t-Bumeoc), 2-(2′- and4′-pyridyl)ethyl carbamate (Pyoc), 2-(N,N-dicyclohexylcarboxamido)ethylcarbamate, t-butyl carbamate (BOC), 1-adamantyl carbamate (Adoc), vinylcarbamate (Voc), allyl carbamate (Alloc), 1-isopropylallyl carbamate(Ipaoc), cinnamyl carbamate (Coc), 4-nitrocinnamyl carbamate (Noc),8-quinolyl carbamate, N-hydroxypiperidinyl carbamate, alkyldithiocarbamate, benzyl carbamate (Cbz), p-methoxybenzyl carbamate (Moz),p-nitobenzyl carbamate, p-bromobenzyl carbamate, p-chlorobenzylcarbamate, 2,4-dichlorobenzyl carbamate, 4-methylsulfinylbenzylcarbamate (Msz), 9-anthrylmethyl carbamate, diphenylmethyl carbamate,2-methylthioethyl carbamate, 2-methylsulfonylethyl carbamate,2-(p-toluenesulfonyl)ethyl carbamate, [2-(1,3-dithianyl)]methylcarbamate (Dmoc), 4-methylthiophenyl carbamate (Mtpc),2,4-dimethylthiophenyl carbamate (Bmpc), 2-phosphonioethyl carbamate(Peoc), 2-triphenylphosphonioisopropyl carbamate (Ppoc),1,1-dimethyl-2-cyanoethyl carbamate, m-chloro-p-acyloxybenzyl carbamate,p-(dihydroxyboryl)benzyl carbamate, 5-benzisoxazolylmethyl carbamate,2-(trifluoromethyl)-6-chromonylmethyl carbamate (Tcroc), m-nitrophenylcarbamate, 3,5-dimethoxybenzyl carbamate, o-nitrobenzyl carbamate,3,4-dimethoxy-6-nitrobenzyl carbamate, phenyl(o-nitrophenyl)methylcarbamate, phenothiazinyl-(10)-carbonyl derivative,N′-p-toluenesulfonylaminocarbonyl derivative, N′-phenylaminothiocarbonylderivative, t-amyl carbamate, S-benzyl thiocarbamate, p-cyanobenzylcarbamate, cyclobutyl carbamate, cyclohexyl carbamate, cyclopentylcarbamate, cyclopropylmethyl carbamate, p-decyloxybenzyl carbamate,2,2-dimethoxycarbonylvinyl carbamate, o-(N,N-dimethylcarboxamido)benzylcarbamate, 1,1-dimethyl-3-(N,N-dimethylcarboxamido)propyl carbamate,1,1-dimethylpropynyl carbamate, di(2-pyridyl)methyl carbamate,2-furanylmethyl carbamate, 2-iodoethyl carbamate, isoborynl carbamate,isobutyl carbamate, isonicotinyl carbamate,p-(p′-methoxyphenylazo)benzyl carbamate, 1-methylcyclobutyl carbamate,1-methylcyclohexyl carbamate, 1-methyl-1-cyclopropylmethyl carbamate,1-methyl-1-(3,5-dimethoxyphenyl)ethyl carbamate,1-methyl-1-(p-phenylazophenyl)ethyl carbamate, 1-methyl-1-phenylethylcarbamate, 1-methyl-1-(4-pyridyl)ethyl carbamate, phenyl carbamate,p-(phenylazo)benzyl carbamate, 2,4,6-tri-t-butylphenyl carbamate,4-(trimethylammonium)benzyl carbamate, 2,4,6-trimethylbenzyl carbamate,formamide, acetamide, chloroacetamide, trichloroacetamide,trifluoroacetamide, phenylacetamide, 3-phenylpropanamide, picolinamide,3-pyridylcarboxamide, N-benzoylphenylalanyl derivative, benzamide,p-phenylbenzamide, o-nitophenylacetamide, o-nitrophenoxyacetamide,acetoacetamide, (N′-dithiobenzyloxycarbonylamino)acetamide,3-(p-hydroxyphenyl)propanamide, 3-(o-nitrophenyl)propanamide,2-methyl-2-(o-nitrophenoxy)propanamide,2-methyl-2-(o-phenylazophenoxy)propanamide, 4-chlorobutanamide,3-methyl-3-nitrobutanamide, o-nitrocinnamide, N-acetylmethioninederivative, o-nitrobenzamide, o-(benzoyloxymethyl)benzamide,4,5-diphenyl-3-oxazolin-2-one, N-phthalimide, N-dithiasuccinimide (Dts),N-2,3-diphenylmaleimide, N-2,5-dimethylpyrrole,N-1,1,4,4-tetramethyldisilylazacyclopentane adduct (STABASE),5-substituted 1,3-dimethyl-1,3,5-triazacyclohexan-2-one, 5-substituted1,3-dibenzyl-1,3,5-triazacyclohexan-2-one, 1-substituted3,5-dinitro-4-pyridone, N-methylamine, N-allylamine,N-[2-(trimethylsilyl)ethoxy]methylamine (SEM), N-3-acetoxypropylamine,N-(1-isopropyl-4-nitro-2-oxo-3-pyroolin-3-yl)amine, quaternary ammoniumsalts, N-benzylamine, N-di(4-methoxyphenyl)methylamine,N-5-dibenzosuberylamine, N-triphenylmethylamine (Tr),N-[(4-methoxyphenyl)diphenylmethyl]amine (MMTr),N-9-phenylfluorenylamine (PhF),N-2,7-dichloro-9-fluorenylmethyleneamine, N-ferrocenylmethylamino (Fcm),N-2-picolylamino N′-oxide, N-1,1-dimethylthiomethyleneamine,N-benzylideneamine, N-p-methoxybenzylideneamine,N-diphenylmethyleneamine, N-[(2-pyridyl)mesityl]methyleneamine,N—(N′,N′-dimethylaminomethylene)amine, N,N′-isopropylidenediamine,N-p-nitrobenzylideneamine, N-salicylideneamine,N-5-chlorosalicylideneamine,N-(5-chloro-2-hydroxyphenyl)phenylmethyleneamine,N-cyclohexylideneamine, N-(5,5-dimethyl-3-oxo-1-cyclohexenyl)amine,N-borane derivative, N-diphenylborinic acid derivative,N-[phenyl(pentacarbonylchromium- or tungsten)carbonyl]amine, N-copperchelate, N-zinc chelate, N-nitroamine, N-nitrosoamine, amine N-oxide,diphenylphosphinamide (Dpp), dimethylthiophosphinamide (Mpt),diphenylthiophosphinamide (Ppt), dialkyl phosphoramidates, dibenzylphosphoramidate, diphenyl phosphoramidate, benzenesulfenamide,o-nitrobenzenesulfenamide (Nps), 2,4-dinitrobenzenesulfenamide,pentachlorobenzenesulfenamide, 2-nitro-4-methoxybenzenesulfenamide,triphenylmethylsulfenamide, 3-nitropyridinesulfenamide (Npys),p-toluenesulfonamide (Ts), benzenesulfonamide,2,3,6,-trimethyl-4-methoxybenzenesulfonamide (Mtr),2,4,6-trimethoxybenzenesulfonamide (Mtb),2,6-dimethyl-4-methoxybenzenesulfonamide (Pme),2,3,5,6-tetramethyl-4-methoxybenzenesulfonamide (Mte),4-methoxybenzenesulfonamide (Mbs), 2,4,6-trimethylbenzenesulfonamide(Mts), 2,6-dimethoxy-4-methylbenzenesulfonamide (iMds),2,2,5,7,8-pentamethylchroman-6-sulfonamide (Pmc), methanesulfonamide(Ms), β-trimethylsilylethanesulfonamide (SES), 9-anthracenesulfonamide,4-(4′,8′-dimethoxynaphthylmethyl)benzenesulfonamide (DNMBS),benzylsulfonamide, trifluoromethylsulfonamide, and phenacylsulfonamide.Exemplary protecting groups are detailed herein, however, it will beappreciated that the present invention is not intended to be limited tothese protecting groups; rather, a variety of additional equivalentprotecting groups can be readily identified using the above criteria andutilized in the method of the present invention. Additionally, a varietyof protecting groups are described by Greene and Wuts (supra).

As described herein, compounds of the invention may contain “optionallysubstituted” moieties. In general, the term “substituted”, whetherpreceded by the term “optionally” or not, means that one or morehydrogens of the designated moiety are replaced with a suitablesubstituent. Unless otherwise indicated, an “optionally substituted”group may have a suitable substituent at each substitutable position ofthe group, and when more than one position in any given structure may besubstituted with more than one substituent selected from a specifiedgroup, the substituent may be either the same or different at everyposition. Combinations of substituents envisioned by this invention arepreferably those that result in the formation of stable or chemicallyfeasible compounds. The term “stable”, as used herein, refers tocompounds that are not substantially altered when subjected toconditions to allow for their production, detection, and, in certainembodiments, their recovery, purification, and use for one or more ofthe purposes disclosed herein.

Suitable monovalent substituents on a substitutable carbon atom of an“optionally substituted” group are independently halogen;—(CH₂)₀₋₄R^(∘); —(CH₂)₀₋₄OR^(∘); —O—(CH₂)₀₋₄C(O)OR^(∘);—(CH₂)₀₋₄CH(OR^(∘))₂; —(CH₂)₀₋₄SR^(∘); —(CH₂)₀₋₄Ph, which may besubstituted with R^(∘); —(CH₂)₀₋₄O(CH₂)₀₋₁Ph which may be substitutedwith R^(∘); —C═CHPh, which may be substituted with R^(∘); —NO₂; —CN;—N₃; —(CH₂)₀₋₄N(R^(∘))₂; —(CH₂)₀₋₄N(R^(∘))C(O)R^(∘); —N(R^(∘))C(S)R^(∘);—(CH₂)₀₋₄N(R^(∘))C(O)NR^(∘) ₂; —N(R^(∘))C(S)NR^(∘) ₂;—(CH₂)₀₋₄N(R^(∘))C(O)OR^(∘); —N(R^(∘))N(R^(∘))C(O)R^(∘);—N(R^(∘))N(R^(∘))C(O)NR^(∘) ₂; —N(R^(∘))N(R^(∘))C(O)OR^(∘);—(CH₂)₀₋₄C(O)R^(∘); —C(S)R^(∘); —(CH₂)₀₋₄C(O)OR^(∘);—(CH₂)₀₋₄C(O)N(R^(∘))₂; —(CH₂)₀₋₄C(O)SR^(∘); —(CH₂)₀₋₄C(O)OSiR^(∘) ₃;—(CH₂)₀₋₄OC(O)R^(∘); —OC(O)(CH₂)₀₋₄SR—, SC(S)SR^(∘);—(CH₂)₀₋₄SC(O)R^(∘); —(CH₂)₀₋₄C(O)NR^(∘) ₂; —C(S)NR^(∘) ₂; —C(S)SR^(∘);—SC(S)SR^(∘), —(CH₂)₀₋₄OC(O)NR^(∘) ₂; —C(O)N(OR^(∘))R^(∘);—C(O)C(O)R^(∘); —C(O)CH₂C(O)R^(∘); —C(NOR^(∘))R^(∘); —(CH₂)₀₋₄SSR^(∘);—(CH₂)₀₋₄S(O)₂R^(∘); —(CH₂)₀₋₄S(O)₂OR^(∘); —(CH₂)₀₋₄OS(O)₂R^(∘);—S(O)₂NR^(∘) ₂; —(CH₂)₀₋₄S(O)R^(∘); —N(R^(∘))S(O)₂NR^(∘) ₂;—N(R^(∘))S(O)₂R^(∘); —N(OR^(∘))R^(∘); —C(NH)NR^(∘) ₂; —P(O)₂R^(∘);—P(O)R^(∘) ₂; —OP(O)R^(∘) ₂; —OP(O)(OR^(∘))₂; SiR^(∘) ₃; —(C₁₋₄ straightor branched alkylene)O—N(R^(∘))₂; or —(C₁₋₄ straight orbranched)alkylene)C(O)O—N(R^(∘))₂, wherein each R^(∘) may be substitutedas defined below and is independently hydrogen, C₁₋₈ aliphatic, —CH₂Ph,—O(CH₂)₀₋₁Ph, or a 5-6-membered saturated, partially unsaturated, oraryl ring having 0-4 heteroatoms independently selected from nitrogen,oxygen, or sulfur, or, notwithstanding the definition above, twoindependent occurrences of R^(∘), taken together with their interveningatom(s), form a 3-12-membered saturated, partially unsaturated, or arylmono- or polycyclic ring having 0-4 heteroatoms independently selectedfrom nitrogen, oxygen, or sulfur, which may be substituted as definedbelow.

Suitable monovalent substituents on R^(∘) (or the ring formed by takingtwo independent occurrences of R^(∘) together with their interveningatoms), are independently halogen, —(CH₂)₀₋₂R^(), -(haloR^()),—(CH₂)₀₋₂ 0H, —(CH₂)₀₋₂OR^(), —(CH₂)₀₋₂CH(OR^())₂; —O(haloR^()), —CN,—N₃, —(CH₂)₀₋₂C(O)R^(), —(CH₂)₀₋₂C(O)OH, —(CH₂)₀₋₂C(O)OR^(),—(CH₂)₀₋₄C(O)N(R^(∘))₂; —(CH₂)₀₋₂SR^(), —(CH₂)₀₋₂SH, —(CH₂)₀₋₂NH₂,—(CH₂)₀₋₂NHR^(), —(CH₂)₀₋₂NR^() ₂, —NO₂, —SiR^() ₃, —OSiR^() ₃,—C(O)SR^(), —(C₁₋₄ straight or branched alkylene)C(O)OR^(), or—SSR^() wherein each R^() is unsubstituted or where preceded by “halo”is substituted only with one or more halogens, and is independentlyselected from C₁₋₄ aliphatic, —CH₂Ph, —O(CH₂)₀₋₁Ph, or a 5-6-memberedsaturated, partially unsaturated, or aryl ring having 0-4 heteroatomsindependently selected from nitrogen, oxygen, or sulfur. Suitabledivalent substituents on a saturated carbon atom of R^(∘) include ═O and═S.

Suitable divalent substituents on a saturated carbon atom of an“optionally substituted” group include the following: ═O, ═S, ═NNR*₂,═NNHC(O)R*, ═NNHC(O)OR*, ═NNHS(O)₂R*, ═NR*, ═NOR*, —O(C(R*₂))₂₋₃O—, or—S(C(R*₂))₂₋₃S—, wherein each independent occurrence of R* is selectedfrom hydrogen, C₁₋₆ aliphatic which may be substituted as defined below,or an unsubstituted 5-6-membered saturated, partially unsaturated, oraryl ring having 0-4 heteroatoms independently selected from nitrogen,oxygen, or sulfur. Suitable divalent substituents that are bound tovicinal substitutable carbons of an “optionally substituted” groupinclude: —O(CR*₂)₂₋₃O—, wherein each independent occurrence of R* isselected from hydrogen, C₁₋₆ aliphatic which may be substituted asdefined below, or an unsubstituted 5-6-membered saturated, partiallyunsaturated, or aryl ring having 0-4 heteroatoms independently selectedfrom nitrogen, oxygen, or sulfur.

Suitable substituents on the aliphatic group of R* include halogen,—R^(), -(haloR^()), —OH, —OR^(), —O(haloR^()), —CN, —C(O)OH,—C(O)OR^(), —NH₂, —NHR^(), —NR^() ₂, or —NO₂, wherein each R^() isunsubstituted or where preceded by “halo” is substituted only with oneor more halogens, and is independently C₁₋₄ aliphatic, —CH₂Ph,—O(CH₂)₀₋₁Ph, or a 5-6-membered saturated, partially unsaturated, oraryl ring having 0-4 heteroatoms independently selected from nitrogen,oxygen, or sulfur.

Suitable substituents on a substitutable nitrogen of an “optionallysubstituted” group include —R^(†), —NR^(†) ₂, —C(O)R^(†), —C(O)OR^(†),—C(O)C(O)R^(†), —C(O)CH₂C(O)R^(†), —S(O)₂R^(†), —S(O)₂NR^(†) ₂,—C(S)NR^(†) ₂, —C(NH)NR^(†) ₂, or —N(R^(†))S(O)₂R^(†); wherein eachR^(†) is independently hydrogen, C₁₋₆ aliphatic which may be substitutedas defined below, unsubstituted —OPh, or an unsubstituted 5-6-memberedsaturated, partially unsaturated, or aryl ring having 0-4 heteroatomsindependently selected from nitrogen, oxygen, or sulfur, or,notwithstanding the definition above, two independent occurrences ofR^(†), taken together with their intervening atom(s) form anunsubstituted 3-12-membered saturated, partially unsaturated, or arylmono- or bicyclic ring having 0-4 heteroatoms independently selectedfrom nitrogen, oxygen, or sulfur.

Suitable substituents on the aliphatic group of R⁵⁵⁴ are independentlyhalogen, —R^(), -(haloR^()), —OH, —OR^(), —O(haloR^()), —CN,—C(O)OH, —C(O)OR^(), —NH₂, —NHR^(), —NR^() ₂, or —NO₂, wherein eachR^() is unsubstituted or where preceded by “halo” is substituted onlywith one or more halogens, and is independently C₁₋₄ aliphatic, —CH₂Ph,—O(CH₂)₀₋₁Ph, or a 5-6-membered saturated, partially unsaturated, oraryl ring having 0-4 heteroatoms independently selected from nitrogen,oxygen, or sulfur.

As used herein, the term “tautomer” includes two or moreinterconvertable compounds resulting from at least one formal migrationof a hydrogen atom and at least one change in valency (e.g., a singlebond to a double bond, a triple bond to a single bond, or vice versa).The exact ratio of the tautomers depends on several factors, includingtemperature, solvent, and pH. Tautomerizations (i.e., the reactionproviding a tautomeric pair) may be catalyzed by acid or base. Exemplarytautomerizations include keto-to-enol; amide-to-imide; lactam-to-lactim;enamine-to-imine; and enamine-to-(a different) enamine tautomerizations.

As used herein, the term “catalyst” refers to a substance the presenceof which increases the rate and/or extent of a chemical reaction, whilenot being consumed or undergoing a permanent chemical change itself.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS I. Polymerization Systems ofthe Invention

In one aspect, the present invention provides polymerization systems forthe copolymerization of CO₂ and epoxides to produce polycarbonate polyolresins with a high proportion of —OH end-groups. A polymerization systemincludes 1) a metal complex including a permanent ligand set and atleast one ligand that is a polymerization initiator, and 2) a chaintransfer agent having a plurality of sites capable of initiating polymerchains. In some embodiments, a polymerization system further includes aco-catalyst. In certain embodiments, a ligand that is a polymerizationinitiator has a plurality of polymer initiation sites.

I.a. Chain Transfer Agents

Chain transfer agents suitable for the present invention include anycompound having two or more sites capable of initiating chain growth inthe co-polymerization of an epoxide and carbon dioxide. Preferably suchcompounds do not have other functional groups that interfere with thepolymerization.

Suitable chain transfer agents may have a broad array of chemicalstructures. In general, the only requirement is that each molecule ofthe chain transfer agent be capable of initiating two or morepolycarbonate chains, this can occur by several mechanisms including: byring-opening an epoxide monomer, by reacting with carbon dioxidemolecules to yield a moiety capable of sustaining polymer chain growth,or by a combination of these. In some embodiments, a chain transferagent may have two or more functional groups independently capable ofreacting with carbon dioxide or an epoxide; examples of these include,but are not limited to molecules such as diacids, glycols, diols,triols, hydroxyacids, amino acids, amino alcohols, dithiols, mercaptoalcohols, saccharides, catechols, polyethers, etc. In some embodiments,the chain transfer agent may include a multiply active functional groupthat is itself able to react multiple times to initiate more than onepolymer chain. Examples of the latter include, but are not limited tofunctional groups having a single atom capable of reacting multipletimes such as ammonia, primary amines and water, as well as functionalgroups having more than one nucleophilic atom such as amindines,guanidines, urea, boronic acids, ect.

In certain embodiments, chain transfer agents of the present disclosurehave a structure Y-A-(Y)_(n), where:

-   -   each —Y group is independently a functional group capable of        initiating chain growth of epoxide CO₂ copolymers and each Y        group may be the same or different,    -   -A- is a covalent bond or a multivalent compound; and    -   n is an integer between 1 and 10 inclusive.

In some embodiments each Y group is independently selected from thegroup consisting of: —OH, —C(O)OH, —C(OR^(y))OH, —OC(R^(y))OH, —NHR^(y),—NHC(O)R^(y), —NHC═NR^(y); —NR^(y)C═NH; —NR^(y)C(NR^(y) ₂)═NH;—NHC(NR^(y) ₂)═NR^(y); —NHC(O)OR^(y), —NHC(O)NR^(y) ₂; —C(O)NHR^(y),—C(S)NHR^(y), —OC(O)NHR^(y), —OC(S)NHR^(y), —SH, —C(O)SH, —B(OR^(y))OH,—P(O)_(a)(R^(y))_(b)(OR^(y))_(c)(O)_(d)H,—OP(O)_(a)(R^(y))_(b)(OR^(y))_(c)(O)_(d)H, —N(R^(y))OH, —ON(R^(y))H;═NOH, ═NN(R^(y))H, where each occurrence of R^(y) is independently —H,or an optionally substituted radical selected from the group consistingof C₁₋₂₀ aliphatic, C₁₋₂₀ heteroaliphatic, 3- to 12-memberedheterocyclic, and 6- to 12-membered aryl, a and b are each independently0 or 1, c is 0, 1 or 2, d is 0 or 1, and the sum of a, b, and c is 1 or2. In some embodiments, an acidic hydrogen atom bound in any of theabove functional groups may be replaced by a metal atom or an organiccation without departing from the present invention (e.g. —C(O)OH mayinstead be —C(O)O⁻Na⁺, —C(O)O⁻N⁺(R)₄, —C(O)O⁻(Ca²⁺)_(0.5), —C(O)O⁻PPN⁺or —SH, may be —S⁻Na⁺ etc.) such alternatives are specifically includedherein and alternate embodiments employing such salts are implicitlyencompassed by the disclosure and examples herein.

In some embodiments, one or more Y groups are hydroxyl or a hydroxysalt. In certain embodiments, each hydroxyl group is a primary orsecondary alcohol. In other embodiments, a hydroxyl group is bonded toan aromatic or heteroaromatic ring. In certain embodiments, a hydroxylgroup is a phenol. In some embodiments, a hydroxyl group is benzylic,allylic or propargylic. In other embodiments, hydroxyl groups are partof a carbohydrate. In other embodiments, a hydroxyl group is part of apolymer or oligomer such as a polyether, a polyester, a polyvinylalcohol or a hydroxy-functionalized or hydroxy-terminated polyolefin.

In some embodiments, a chain transfer agent is a polyhydric alcohol. Incertain embodiments, a polyhydric alcohol is a diol, while in otherembodiments the polyhydric alcohol is a triol, a tetraol or a higherpolyol. In certain embodiments, n is 1, (i.e. two Y groups are present)and both Y groups are hydroxyl groups (i.e the chain transfer agent is adiol). In some embodiments, two hydroxyl groups are on adjacent carbons(i.e. the chain transfer agent is a glycol).

In some embodiments, two hydroxyl groups are on non-adjacent carbons. Incertain embodiments, two hydroxyl groups are on the opposite ends of achain (i.e. the chain transfer agent is an α-ω diol). In certainembodiments, such α-ω diols include C₃ to C₂₀ aliphatic chains (i.e. -A-is an optionally substituted C₃₋₂₀ aliphatic chain). In certainembodiments, such α-ω diols comprise a polyether (i.e. -A- is apolyether chain). In certain embodiments, such α-ω diols comprise ahydroxy-terminated polyolefin (i.e. -A- is a polyolefin chain). Incertain embodiments, such α-ω diols comprise paraformaldehyde (i.e. -A-is a polyoxymethylene chain).

In certain embodiments, -A- is a covalent bond. For example, whenY-A-(Y)_(n) is oxalic acid, -A- is a covalent bond.

In some embodiments, one —OH group of a diol is phenolic and the otheris aliphatic. In other embodiments each hydroxy group is phenolic. Incertain embodiments, a chain transfer agent is an optionally substitutedcatechol, resorcinol or hydroquinone derivative.

In some embodiments where a Y-group is —OH, the —OH group is an enoltautomer of a carbonyl group. In some embodiments where a Y group is—OH, the —OH group is a carbonyl hydrate or a hemiacetal.

In other embodiments where n is 1, only one Y group is —OH, and theother Y group is selected from the group consisting of: —C(O)OH,—C(OR^(y))OH, —OC(R^(y))OH, —NHR^(y), —NHC(O)R^(y), —NHC(O)OR^(y),—C(O)NHR^(y), —C(S)NHR^(y), —OC(O)NHR^(y), —OC(S)NHR^(y), —SH, —C(O)SH,—B(OR^(y))OH, —P(O)_(a)(R^(y))_(b)(OR^(y))_(c)OH,—OP(O)_(a)(R^(y))_(b)(OR^(y))_(c)OH, —N(R^(y))OH, —ON(R^(y))H; ═NOH,═NN(R^(y))H. In particular embodiments, n is 1, one Y group is —OH, andthe other Y group is selected from the group consisting of —SH, —C(O)OH,—NHR^(y), and —C(O)NHR^(y). In certain embodiments, n is 1, one Y groupis —OH, and the other Y group is —C(O)OH. In other embodiments where nis 1, one Y group is —OH and the other Y group is —SH. In otherembodiments where n is 1, one Y group is —OH and one Y group is—NHR^(y). In certain embodiments, n is 2, and each Y group is —OH (i.e.the chain transfer agent is a triol). In particular embodiments where nis 2, two Y groups are —OH, and the third Y group is selected from thegroup consisting of —SH, —C(O)OH, —NHR^(y), and —C(O)NHR^(y). In otherembodiments where n is 2, only one Y group is —OH, while the other two Ygroups are independently selected from the group consisting of —SH,—C(O)OH, —NHR^(y), and —C(O)NHR^(y).

In some embodiments, polyalcohol chain transfer agents encompassnaturally occurring materials such as sugar alcohols, carbohydrates,saccharides, polysaccharides, starch, starch derivatives, lignins,lignans, partially hydrolyzed triglycerides, and the like, as well asknown derivatives of any of these materials. In certain embodiments, achain transfer agent is starch. In certain embodiments, a chain transferagent is isosorbide.

In other embodiments, at least one Y group of a chain transfer agent isan amine. In some embodiments, at least one Y group is a primary amine.In other embodiments, at least one Y group is a secondary amine. Incertain embodiments, at least one Y group is an aniline or anilinederivative. In some embodiments, at least one Y group is an N—H groupthat is part of a heterocycle.

In certain embodiments, a chain transfer agent is a polyamine. In someembodiments, a chain transfer agent is a diamine. In other embodiments,a chain transfer agent is a triamine, tetraamine or a higher amineoligomer.

In certain embodiments, at least one Y group is an amine and one or moreadditional Y groups are independently selected from the group consistingof —OH, —C(O)OH, —C(OR^(y))OH, —OC(R^(y))OH, —NHC(O)R^(y),—NHC(O)OR^(y), —C(O)NHR^(y), —C(S)NHR^(y), —OC(O)NHR^(y), —OC(S)NHR^(y),—SH, —C(O)SH, —B(OR^(y))OH, —P(O)_(a)(R^(y))_(b)(OR^(y))_(c)OH,—OP(O)_(a)(R^(y))_(b)(OR^(y))_(c)OH, —N(R^(y))OH, —ON(R^(y))H; ═NOH,═NN(R^(y))H. In certain embodiments, at least one Y group is an amineand one or more additional Y groups are independently selected from thegroup consisting of —OH, —SH, —C(O)OH, and —C(O)NHR^(y). In someembodiments, a chain transfer agent is an amino alcohol. In someembodiments, a chain transfer agent is an amino acid. In someembodiments, a chain transfer agent is an amino thiol. In someembodiments, a chain transfer agent is an amino amide.

In some embodiments, at least one Y group is a carboxylic acid or a saltthereof. In some embodiments, all Y groups present are carboxylic acidsalts thereof, while in other embodiments, one or more carboxylic acid Ygroups are present along with one or more other functional groups thatcan initiate the copolymerization. In certain embodiments, at least oneY group is a benzoic acid derivative.

In certain embodiments, a chain transfer agent is a diacid, a triacid ora higher polyacid. In some embodiments, a chain transfer agent is adiacid. In certain embodiments, n is 1, and both Y groups present arecarboxylic acids. In certain embodiments, a diacid is phthalic acid,isophthalic acid, terephthalic acid. In certain embodiments, a diacid ismaleic acid, succinic acid, malonic acid, glutaric acid, adipic acid,pimelic acid, suberic acid, or azelaic acid. In some embodiments, achain transfer agent is a triacid. In certain embodiments, a triacid iscitric acid, isocitric acid, cis- or trans-aconitic acid,propane-1,2,3-tricarboxylic acid or trimesic acid.

In certain embodiments, at least one Y group is a carboxylic acid orcarboxylate and one or more additional Y groups are independentlyselected from the group consisting of —OH, —C(OR^(y))OH, —OC(R^(y))OH,—NHR^(y), —NHC(O)R^(y), —NHC(O)OR^(y), —C(O)NHR^(y), —C(S)NHR^(y),—OC(O)NHR^(y), —OC(S)NHR^(y), —SH, —C(O)SH, —B(OR^(y))OH,—P(O)_(a)(R^(y))_(b)(OR^(y))_(c)OH, —OP(O)_(a)(R^(y))_(b)(OR^(y))_(c)OH,—N(R^(y))OH, —ON(R^(y))H; ═NOH, ═NN(R^(y))H. In certain embodiments, atleast one Y group is a carboxylic acid and one or more additional Ygroups are independently selected from the group consisting of —OH, —SH,—NHR^(y), and —C(O)NHR^(y).

In some embodiments, a chain transfer agent is an amino acid. In certainembodiments, amino acid chain transfer agents include the naturallyoccurring amino acids. In certain embodiments, amino acid chain transferacids include peptides. In some embodiments, the peptides containbetween 2 and about 20 amino acid residues. In other embodiments, thechain transfer agent is a thiol acid.

In some embodiments, the chain transfer agent is a hydroxy acid. In someembodiments, hydroxy acids are alpha-hydroxy acids. In certainembodiments an alpha hydroxy acid is selected from the group consistingof: glycolic acid, DL-lactic acid, D-lactic acid, L-lactic, citric acidand mandelic acid. In some embodiments, a hydroxy acid is a beta-hydroxyacid. In certain embodiments, a beta hydroxy acid is selected from thegroup consisting of: 3-hydroxypropionic acid, DL 3-hydroxybutryic acid,D-3 hydroxybutryic acid, L 3-hydroxybutyric acid, DL-3-hydroxy valericacid, D-3-hydroxy valeric acid, L-3-hydroxy valeric acid, salicylicacid, and derivatives of salicylic acid. In some embodiments, a hydroxyacid is an α-ω hydroxy acid. In certain embodiments, α-ω hydroxy acidsare selected from the group consisting of optionally substituted C₃₋₂₀aliphatic α-ω hydroxy acids. In certain embodiments, an α-ω hydroxy acidis a polyester oligomeric ester.

In some embodiments, where one or more Y groups is a carboxyl group, achain transfer agent is provided as a carboxylate salt. In certainembodiments, a carboxylate salt is a group I or II metal salt. In someembodiments, a carboxylate salt is an ammonium salt. In certainembodiments, an ammonium cation is NH₄ ⁺. In some embodiments, anammonium cation is a protonated primary, secondary, or tertiary amine.In some embodiments, a salt is a quaternary ammonium salt. In someembodiments, a quaternary ammonium cation of a salt is tetramethyl,tetrabutyl, or trahexylammonium ammonium. In certain embodiments, acarboxylate salt is a phosphonium carboxylate.

In other embodiments, at least one Y group of a chain transfer agent isa thiol. In some embodiments, at least one Y group is a primary thiol.In other embodiments, at least one Y group is a secondary or tertiarythiol. In certain embodiments, at least one Y group is a thiophenol orthiophenol derivative.

In certain embodiments, a chain transfer agent is a polythiol. In someembodiments, a chain transfer agent is a dithiol. In some embodiments, achain transfer agent is a trithiol, higher thiol oligomer.

In certain embodiments, at least one Y group is a thiol and one or moreadditional Y groups are independently selected from the group consistingof —OH, —C(O)OH, —C(OR^(y))OH, —OC(R^(y))OH, —NHR^(y), —NHC(O)R^(y),—NHC(O)OR^(y), —C(O)NHR^(y), —C(S)NHR^(y), —OC(O)NHR^(y), —OC(S)NHR^(y),—C(O)SH, —B(OR^(y))OH, —P(O)_(a)(R^(y))_(b)(OR^(y))_(c)OH,—OP(O)_(a)(R^(y))_(b)(OR^(y))_(c)OH, —N(R^(y))OH, —ON(R^(y))H; ═NOH,═NN(R^(y))H. In certain embodiments, at least one Y group is a thiol andone or more additional Y groups are independently selected from thegroup consisting of —OH, —NHR^(y), —C(O)OH, and —C(O)NHR^(y). In someembodiments, a chain transfer agent is a thio alcohol. In someembodiments, a chain transfer agent is an amino thiol. In someembodiments, a chain transfer agent is a thiol carboxylic acid.

In certain embodiments, a Y group of a chain transfer agent is an activeNH-containing functional group. In certain embodiments, a nitrogen atomof the NH-containing functional group is nucleophilic. In certainembodiments, a active NH-containing functional group is selected fromthe group consisting of C-linked amides, N-linked amides, O-linkedcarbamates N-linked carbamates, ureas, guanidines, amidines, hydrazones,and N- or C-linked thioamides. In certain embodiments, one or more Ygroups is a primary amide.

In certain embodiments, polymerization systems of the present inventioninclude only one chain transfer agent, while in other embodiments,mixtures of two or more chain transfer agents are used.

In certain embodiments, polymerization systems of the present inventioninclude a solvent in which a chain transfer agent dissolves. In certainembodiments, a chain transfer agent is poorly soluble in the epoxide,but is soluble in a mixture of epoxide and another solvent added to thereaction mixture. In certain embodiments, the solvent added to thepolymerizations system is chosen from the group consisting of esters,nitriles, ketones, aromatic hydrocarbons, ethers, amines andcombinations of two or more of these.

In some embodiments, a polymerization initiator includes a multiplyactive functional group that is itself able to react multiple times toinitiate more than one polymer chain. One subset of such multiply-activefunctional groups react multiple times at the same atom. Examples ofsuch groups include, but are not limited to ammonia, primary amines,hydrogen sulfide and water, all of which remain nucleophilic after thefirst addition and are thereby able to react again initiating additionalpolymer chains. Another subset of multiply active functional groups canreact at different atoms in the functional group to initiate multiplechains. Examples of such groups include, but are not limited toguanidines, ureas, boronic acids, hydroxyl amines, and amidines.

In some embodiments, a chain transfer agent may contain a singlemultiply active functional group. In some embodiments, the chaintransfer agent may contain a single multiply active functional group inaddition to one or more of the Y-groups described above. In certainembodiments, a chain transfer agent may contain two or more multiplyactive functional groups. In certain embodiments, a chain transfer agentmay contain two or more multiply active functional groups in combinationwith one or more of the Y groups described hereinabove.

I.b Metal Centered Catalysts

In certain embodiments, provided metal complexes are transition metalcatalysts. Thus, in some embodiments, polymerization systems of thepresent invention incorporate transition metal catalysts capable ofcatalyzing the copolymerization of carbon dioxide and epoxides. Incertain embodiments, the polymerization systems include any of thecatalysts disclosed in U.S. Pat. Nos. 7,304,172, and 6,870,004; in PCTApplication Numbers WO2008136591A1, WO2008150033A1, PCT/US09/042926; andPCT/US09/054773 and in Chinese Patent Application NumbersCN200710010706, and CN200810229276, the entirety of each of which ishereby incorporated herein by reference.

In certain embodiments, polymerization systems of the present inventioninclude metal complexes denoted L_(p)-M-(L_(I))_(m), where L_(p) is apermanent ligand set, M is a metal atom, and L_(I) is a ligand that is apolymerization initiator, and m is an integer between 0 and 2 inclusiverepresenting the number of initiating ligands present.

I.b.1 Metal Atoms

In some embodiments, a metal atom, M, is selected from periodic tablegroups 3-13, inclusive. In certain embodiments, M is a transition metalselected from periodic table groups 5-12, inclusive. In someembodiments, M is a transition metal selected from periodic table groups4-11, inclusive. In certain embodiments, M is a transition metalselected from periodic table groups 5-10, inclusive. In certainembodiments, M is a transition metal selected from periodic table groups7-9, inclusive. In some embodiments, M is selected from the groupconsisting of Cr, Mn, V, Fe, Co, Mo, W, Ru, Al, and Ni. In someembodiments, M is a metal atom selected from the group consisting of:cobalt; chromium; aluminum; titanium; ruthenium, and manganese. In someembodiments, M is cobalt. In some embodiments, M is chromium. In someembodiments, M is aluminum.

In certain embodiments, a metal complex is a zinc, cobalt, chromium,aluminum, titanium, ruthenium, or manganese complex. In certainembodiments, a metal complex is an aluminum complex. In otherembodiments, a metal complex is a chromium complex. In yet otherembodiments, a metal complex is a zinc complex. In certain otherembodiments, a metal complex is a titanium complex. In still otherembodiments, a metal complex is a ruthenium complex. In certainembodiments, a metal complex is a manganese complex. In certainembodiments, a metal complex is cobalt complex. In certain embodimentswhere a metal complex is a cobalt complex, the cobalt metal has anoxidation state of +3 (i.e., Co(III)). In other embodiments, the cobaltmetal has an oxidation state of +2 (i.e., Co(II)).

I.b.2 Permanent Ligand Sets

A permanent ligand set ‘L_(p)’ comprises one or more ligands that remaincoordinated with a metal center throughout the catalytic cycle. This isin contrast to other ligands such as polymerization initiators, monomermolecules, polymer chains, and solvent molecules that may participate inthe catalytic cycle or may be exchanged under the polymerizationconditions.

In certain embodiments, a permanent ligand set comprises a singlemultidentate ligand that remains associated with the metal center duringcatalysis. In some embodiments, the permanent ligand set includes two ormore ligands that remain associated with the metal center duringcatalysis. In some embodiments, a metal complex comprises a metal atomcoordinated to a single tetradentate ligand while in other embodiments,a metal complex comprises a chelate containing a plurality of individualpermanent ligands. In certain embodiments, a metal complex contains twobidentate ligands. In some embodiments, a metal complex contains atridentate ligand.

In various embodiments, tetradentate ligands suitable for metalcomplexes of the present invention may include, but are not limited to:salen derivatives 1, derivatives of salan ligands 2,bis-2-hydroxybenzamido derivatives 3, derivatives of the Trost ligand 4,porphyrin derivatives 5, derivatives of tetrabenzoporphyrin ligands 6,derivatives of corrole ligands 7, phthalocyaninate derivatives 8, anddibenzotetramethyltetraaza[14]annulene (tmtaa) derivatives 9 or 9′.

-   -   wherein,    -   Q, at each occurrence is independently O or S;    -   R¹ and R^(1′) are independently selected from the group        consisting of: —H, optionally substituted C₁ to C₁₂ aliphatic;        optionally substituted 3- to 14-membered carbocycle; optionally        substituted 3- to 14-membered heterocycle; and R²¹;    -   R² and R^(2′) are independently selected from the group        consisting of: —H; optionally substituted C₁ to C₁₂ aliphatic;        optionally substituted 3- to 14-membered carbocycle; optionally        substituted 3- to 14-membered heterocycle; R¹⁴; R²⁰; and R²¹;    -   R³ and R^(3′) are independently selected from the group        consisting of: —H; optionally substituted C₁ to C₁₂ aliphatic;        optionally substituted 3- to 14-membered carbocycle; optionally        substituted 3- to 14-membered heterocycle, and R²¹;    -   R^(c) at each occurrence is independently selected from the        group consisting of: —H; optionally substituted C₁ to C₁₂        aliphatic; an optionally substituted 3- to 14-membered        carbocycle; an optionally substituted 3- to 14 membered        heterocycle; R²⁰; and R²¹, where two or more R^(c) groups may be        taken together with intervening atoms to form one or more        optionally substituted rings and, when two R^(c) groups are        attached to the same carbon atom, they may be taken together        along with the carbon atom to which they are attached to form a        moiety selected from the group consisting of: an optionally        substituted 3- to 8-membered spirocyclic ring, a carbonyl, an        oxime, a hydrazone, and an imine;    -   R^(d) at each occurrence is independently selected from the        group consisting of: optionally substituted C₁ to C₁₂ aliphatic;        optionally substituted 3- to 14-membered carbocycle; optionally        substituted 3- to 14-membered heterocycle; R²⁰; and R²¹, where        two or more R^(d) groups may be taken together with intervening        atoms to form one or more optionally substituted rings; and    -   represents an optionally substituted moiety covalently linking        two nitrogen atoms,    -   where any of [R^(2′) and R^(3′)], [R² and R³], [R¹ and R²], and        [R^(1′) and R^(2′)] may optionally be taken together with        intervening atoms to form one or more rings which may in turn be        substituted with one or more groups selected from R¹⁴; R²⁰; and        R²¹; and where        -   R¹⁴ at each occurrence is independently selected from the            group consisting of: halogen; optionally substituted C₁ to            C₁₂ aliphatic; optionally substituted 3- to 14-membered            carbocycle; optionally substituted 3- to 14-membered            heterocycle; —OR¹⁰; —OC(O)R¹³; —OC(O)OR¹³; —OC(O)NR¹¹R¹²;            —CN; —CNO; —C(R¹³)_(z)H_(3-z)); —C(O)R¹³; —C(O)OR¹³;            —C(O)NR¹¹R¹²; —NR¹¹R¹²; —NR¹¹C(O)R¹³; —NR¹¹C(O)OR¹³;            —NR¹¹SO₂R¹³; —N⁺R¹¹R¹²R¹³X⁻; —P⁻(R¹¹)₃X⁻;            —P(R¹¹)₃═N⁺═P(R¹¹)₃X⁻; —As⁺R¹¹R¹²R¹³X⁻; —NCO; —N₃; —NO₂;            —S(O)_(x)R¹³; and —SO₂NR¹¹R¹²,        -   R²⁰ at each occurrence is independently selected from the            group consisting of: halogen; —OR¹⁰; —OC(O)R¹³; —OC(O)OR¹³;            —N⁺(R¹¹)₃X⁻; —P⁺(R¹¹)₃X⁻; —P(R¹¹)₃═N^(|)═P(R¹¹)₃X⁻;            —As^(|)R¹¹R¹²R¹³X⁻; —OC(O)NR¹¹R¹²; —CN; —CNO; —C(O)R¹³;            —C(O)OR¹³; —C(O)NR¹¹R¹²; —C(R¹³)_(z)H_(3-z)); —NR¹¹R¹²;            —NR¹¹C(O)R¹³; —NR¹¹C(O)OR¹³; —NCO; —NR¹¹SO₂R¹³,            —S(O)_(x)R¹³; —S(O)₂NR¹¹R¹²; —NO₂; —N₃; and            —Si(R¹³)_((3-z))[(CH₂)_(k)R¹⁴]_(z),        -   R²¹ at each occurrence is independently selected from the            group consisting of: —(CH₂)_(k)R²⁰;            —(CH₂)_(k)—Z″—(CH₂)_(k)R²⁰; —C(R¹⁷)_(z)H_((3-z));            —(CH₂)_(k)C(R¹⁷)_(z)H_((3-z));            —(CH₂)_(m)—Z″—(CH₂)_(m)C(R¹⁷)_(z)H_((3-z));            —(CH₂)_(k)—Z″—R¹⁶;        -   X⁻ is any anion,        -   Z″ is a divalent linker selected from the group consisting            of —(C═CH)_(a)—; —(CH≡CH)_(a)—; —C(O)—; —C(═NOR¹¹)—;            —C(═NNR¹¹R¹²)—; —O—; —OC(O)—; —C(O)O—; —OC(O)O—; —N(R¹¹)—;            —N(C(O)R¹³)—; —C(O)NR¹³)—; —N(C(O)R¹³)O—; —NR¹³C(O)R¹³N—;            —S(O)_(x)—; a polyether; and a polyamine,        -   R¹⁰ at each occurrence is independently selected from the            group consisting of: —H; optionally substituted C₁₋₁₂            aliphatic; an optionally substituted 3- to 14-membered            carbocycle; an optionally substituted 3- to 14-membered            heterocycle —S(O)₂R¹³; —Si(R¹⁵)₃; —C(O)R¹³; and a hydroxyl            protecting group,        -   R¹¹ and R¹² at each occurrence are independently selected            from the group consisting of: —H; optionally substituted C₁            to C₁₂ aliphatic; an optionally substituted 3- to            14-membered carbocycle; an optionally substituted 3- to            14-membered heterocycle; where two or more R¹¹ or R¹² groups            can optionally be taken together with intervening atoms to            form an optionally substituted 3- to 10-membered ring,        -   R¹³ at each occurrence is independently selected from the            group consisting of: —H; optionally substituted C₁ to C₁₂            aliphatic; an optionally substituted 3- to 14-membered            carbocycle; and optionally substituted 3- to 14-membered            heterocycle, where two or more R¹³ groups on the same            molecule may optionally be taken together to form ring.        -   R¹⁵ at each occurrence is independently selected from the            group consisting of: optionally substituted C₁-₁₂ aliphatic,            an optionally substituted 3- to 14-membered carbocycle; and            an optionally substituted 3- to 14-membered heterocycle,    -   a is 1, 2, 3, or 4,    -   k is independently at each occurrence an integer from 1 to 8,        inclusive,    -   m is 0 or an integer from 1 to 8, inclusive,    -   q is 0 or an integer from 1 to 5, inclusive,    -   x is 0, 1, or 2, and    -   z is 1, 2, or 3.

In certain embodiments, of complexes 1 through 4,

is selected from the group consisting of a C₃₋₁₄ carbocycle, a C₆₋₁₀aryl group, a 3- to 14-membered heterocycle, and a 5- to 10-memberedheteroaryl group; a polyether group, or an optionally substituted C₂₋₂₀aliphatic group, wherein one or more methylene units are optionally andindependently replaced by —NR^(y)—, —N(R^(y))C(O)—, —C(O)N(R^(y))—,—OC(O)N(R^(y))—, —N(R^(y))C(O)O—, —OC(O)O—, —O—, —C(O)—, —OC(O)—,—C(O)O—, —S—, —SO—, —SO₂—, —C(═S)—, —C(═NR^(y))—, —C(═NOR^(y))— or—N═N—.

In some embodiments, one or more of the substituents on metal complexes1 through 9′ is an activating moiety

where “

” represents a covalent linker containing one or more atoms selectedfrom the group consisting of C, O, N, S, and Si; “Z” is an activatingfunctional group having co-catalytic activity in epoxide CO₂copolymerization, and p is an integer from 1 to 4 indicating the numberof individual activating functional groups present on a given activatingmoiety.

In certain embodiments, the linker moiety “

” is as described in co-pending PCT application number PCT/US09/54773.In some embodiments, the one or more Z group(s) present on theactivating moiety is independently selected from the group consisting ofPPN⁺ derivatives (—PR₂═N⁺═PR₃); ammonium salts; phosphonium salts; or anoptionally substituted N-linked imidazolium, thiazolium, or oxazoliumgroup. In certain embodiments, a Z group is an optionally substitutedN-linked piperidine or N-linked pyrrolidine. In some embodiments, a Zgroup is an optionally substituted guanidine. In other embodiments, a Zgroup is any of those described in PCT/US09/54773.

In some embodiments, provided metal complexes have a structure selectedfrom the group consisting of:

wherein:

M, L_(I), m R¹, R^(1′), R², R^(2′), R³, R^(3′) and R¹¹ are as definedabove.

In some embodiments, a permanent ligand set is a salen ligand. Incertain embodiments, a metal complex is a metallosalenate. In certainembodiments, a metal complex is a cobalt salen complex. In certainembodiments, a metal complex is a chromium salen complex. In otherembodiments, a metal complex is an aluminum salen complex.

In certain embodiments, metal complexes of the present invention havethe formula:

wherein:

-   -   M is the metal atom;    -   L_(I) is a nucleophile capable of ring opening an epoxide;    -   m is an integer from 0-2 inclusive; and

is the permanent ligand set;

-   -   wherein        is as defined previously and each R′ independently represents        one or more substituents optionally present on the phenyl rings.    -   In certain embodiments, each R′ is independently an R^(d) group        or a

group, where two or more adjacent R′ groups can be taken together toform an optionally substituted saturated, partially unsaturated, oraromatic 3- to 12-membered ring containing 0 to 4 heteroatoms,

In certain embodiments, the

moiety is selected from the group consisting of:

where

-   -   R^(c) and R′ are as previously defined,    -   Y is a divalent linker selected from the group consisting of:        —N(R¹¹)—; —O—; —S(O)_(x)—; —(CH₂)_(k)—; —C(O)—; —C(═NOR¹⁰)—;        —C(R^(c))—H_(2-x)—; a polyether; an optionally substituted 3- to        8-membered carbocycle; and an optionally substituted 3- to        8-membered heterocycle,    -   q is 0 or an integer from 1 to 5 inclusive, and    -   x is 0, 1, or 2,

In certain embodiments provided metal complexes have a structureselected from the group consisting of:

wherein:

-   -   M, R^(c), R′, L_(I), and m are as defined above;    -   R^(4a), R^(4a′), R^(5a), R^(5a′), R^(6a), R^(6a′), R^(7a), and        R^(7a′) are each independently hydrogen, a

group, halogen. —NO₂, —CN, —SR¹³, —S(O)R¹³, —S(O)₂R^(—), —NR¹¹C(O)R¹³,—OC(O)R¹³, —CO₂R¹³, —NCO, —N₃, —OR¹⁰, —OC(O)NR¹¹R¹², —Si(R¹³)₃,—NR¹¹R¹², —NR¹¹C(O)R¹³, and —NR¹¹C(O)OR¹³; or an optionally substitutedradical selected from the group consisting of C₁₋₂₀ aliphatic; C₁₋₂₀heteroaliphatic; 6- to 10-membered aryl; 5- to 10-membered heteroaryl;and 3- to 7-membered heterocyclic, where [R^(1a) and R^(4a)], [R^(1a′)and R^(4A′)] and any two adjacent R^(4a), R^(4a′), R^(5a), R^(5a′),R^(6a), R^(6a′), R^(7a), and R^(7a′) groups can be taken together withintervening atoms to form one or more optionally substituted ringsoptionally containing one or more heteroatoms;

-   -   n is 0 or an integer from 1 to 8, inclusive; and    -   p is 0 or an integer from 1 to 4, inclusive.

In some embodiments, R^(1a), R^(1a′), R^(4a), R^(4a′), R^(6a), andR^(6a′) are each —H. In some embodiments, R^(5a), R^(5a′), R^(7a) andR^(7a′) are each optionally substituted C₁-C₁₂ aliphatic. In someembodiments, R^(4a), R^(4a′), R^(5a), R^(5a′), R^(6a), R^(6a′), R^(7a),and R^(7a′) are each independently selected from the group consistingof: —H, —SiR₃; methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl,t-butyl, isoamyl, t-amyl, thexyl, and trityl. In some embodiments,R^(1a), R^(1a′), R^(4a), R^(4a′), R^(6a), and R^(6a′) are each —H. Insome embodiments, R^(7a) is selected from the group consisting of —H;methyl; ethyl; n-propyl; i-propyl; n-butyl; sec-butyl; t-butyl; isoamyl;t-amyl; thexyl; and trityl. In some embodiments, R^(5a) and R^(7a) areindependently selected from the group consisting of —H; methyl; ethyl;n-propyl; i-propyl; n-butyl; sec-butyl; t-butyl; isoamyl; t-amyl;thexyl; and trityl. In certain embodiments, one or more of R^(5a),R^(5a′), R^(7a) and R^(7a′) is a

group. In some embodiments, R^(5a) and R^(5a′) are each a

group. In some embodiments, R^(5a) is a

group and R^(5a′) is C₁₋₈ aliphatic. In some embodiments, R^(7a) andR^(7a′) are each a

group. In some embodiments, R^(7a) is a

group and R^(7a′) is C₁₋₈ aliphatic.

In certain embodiments, provided metal complexes have a structureselected from the group consisting of:

where R^(1a) through R^(7a′) are as defined above.

In certain embodiments, provided metal complexes have a structureselected from the group consisting of:

where R^(5a), R^(5a′), R^(7a), and R^(7a′) are as defined above. Incertain embodiments, each pair of substituents on the salicaldehydeportions of the complexes above are the same (i.e. R^(5a) & R^(5a′) arethe same and R^(7a) & R^(7a′) are the same). In other embodiments, atleast one of R^(5a) & R^(5a′) or R^(7a) & R^(7a) are different from oneanother.

In certain embodiments, a metal complex has formula III:

In certain embodiments, a metal complex has formula IV:

In certain embodiments, wherein a metal complex has formula V:

wherein:

-   -   R^(c), R^(d), L_(I), m, and q are as described above, and    -   R⁴, R^(4′), R⁵, R^(5′), R⁶, R^(6′), R⁷, and R^(7′) are each        independently selected from the group consisting of: —H; —R²⁰;        —R²¹; optionally substituted C₁-C₁₂ aliphatic; optionally        substituted 3- to 14-membered carbocycle; and optionally        substituted 3- to 14-membered heterocycle;    -   where [R¹ and R⁴], [R^(1′) and R^(4′)] and any two adjacent R⁴,        R^(4′), R⁵, R^(5′), R⁶, R^(6′), R⁷, and R^(7′) groups can        optionally be taken together with intervening atoms to form one        or more rings optionally substituted with one or more R²⁰        groups.

In certain embodiments, wherein a metal complex has formula III, R¹,R^(1′), R⁴, R^(4′), R⁶, and R^(6′) are each —H. In certain embodiments,wherein a metal complex has formula III, R⁵, R^(5′), R⁷ and R^(7′) areeach optionally substituted C₁-C₁₂ aliphatic.

In certain embodiments, wherein a metal complex has formula III, R⁴,R^(4′), R⁵, R^(5′), R⁶, R^(6′), R⁷, and R^(7′) are each independentlyselected from the group consisting of: —H, —Si(R¹³)₃;—Si[(CH₂)_(k)R²²]_(z)(R¹³)_((3-z)); methyl, ethyl, n-propyl, i-propyl,n-butyl, sec-butyl, t-butyl, isoamyl, t-amyl, thexyl, trityl,—C(CH₃)Ph₂, —(CH₂)_(p)C[(CH₂)_(p)R²²]_(z)H_((3-z)), and—Si(R¹³)_((3-z))[(CH₂)_(k)R²²]_(z), where p is an integer from 0 to 12inclusive and R²² is selected from the group consisting of: aheterocycle; an amine; a guanidine; —N⁻(R¹¹)₃X⁻; —P⁻(R¹¹)₃X³¹;—P(R¹¹)₂═N⁺═P(R¹¹)₃X⁻; —As⁺(R¹¹)₃X⁻, and optionally substitutedpyridinium.

In certain embodiments, wherein a metal complex has formula III, R⁷ isselected from the group consisting of —H; methyl; ethyl; n-propyl;i-propyl; n-butyl; sec-butyl; t-butyl; isoamyl; t-amyl; thexyl; andtrityl; and R⁵ is selected from the group consisting of—(CH₂)_(p)CH_((3-z))[(CH₂)_(p)R²²]_(z) and—Si(R¹³)_((3-z))[(CH₂)_(k)R²²]_(z).

In certain embodiments, a metal complex has formula IV, R¹, R^(1′), R⁴,R^(4′), R⁶, and R^(6′) are each —H. In certain embodiments, wherein thecomplex is a metallosalenate complex of formula IV, R⁵, R^(5′), R⁷ andR^(7′) are each optionally substituted C₁-C₁₂ aliphatic.

In certain embodiments, wherein a metal complex has formula IV, R⁴,R^(4′), R⁵, R^(5′), R⁶, R^(6′), R⁷, and R^(7′) are each independentlyselected from the group consisting of: —H, —Si(R¹³)₃;—Si(R¹³)_((3-z))[(CH₂)_(k)R²²]_(z); methyl, ethyl, n-propyl, i-propyl,n-butyl, sec-butyl, t-butyl, isoamyl, t-amyl, thexyl, trityl,—(CH₂)_(p)C[(CH₂)_(p)R²²]_(z)H_((3-z)).

In certain embodiments, wherein a metal complex has formula IV, R⁷ isselected from the group consisting of —H; methyl; ethyl; n-propyl;i-propyl; n-butyl; sec-butyl; t-butyl; isoamyl; t-amyl; thexyl; andtrityl; and R⁵ is selected from the group consisting of—(CH₂)_(p)CH_((3-z))[(CH₂)_(p)R²²]_(z) and—Si(R¹³)_((3-z))[(CH₂)_(k)R²²]_(z).

In certain embodiments, wherein a metal complex has formula V, R¹,R^(1′), R⁴, R^(4′), R⁶, and R^(6′) are each —H. In certain embodiments,wherein a complex is a metallosalenate complex of formula V, R⁵, R^(5′),R⁷ and R^(7′) are each optionally substituted C₁-C₁₂ aliphatic.

In certain embodiments, wherein a metal complex has formula V, R⁴,R^(4′), R⁵, R^(5′), R⁶, R^(6′), R⁷, and R^(7′) are each independentlyselected from the group consisting of: —H, —Si(R¹³)₃;—Si[(CH₂)_(k)R²¹]_(z)(R¹³)_((3-z)); methyl, ethyl, n-propyl, i-propyl,n-butyl, sec-butyl, t-butyl, isoamyl, t-amyl, thexyl, trityl,—(CH₂)_(p)CH_((3-z))[(CH₂)_(p)R²²]_(z) and—Si(R¹³)_((3-z))[(CH₂)_(k)R²²]_(z).

In certain embodiments, wherein a metal complex has formula V, R⁷ isselected from the group consisting of —H; methyl; ethyl; n-propyl;i-propyl; n-butyl; sec-butyl; t-butyl; isoamyl; t-amyl; thexyl; andtrityl; and R⁵ is selected from the group consisting of—(CH₂)_(p)CH_((3-z))[(CH₂)_(p)R²²]_(z) and—Si(R¹³)_((3-z))[(CH₂)_(k)R²²]_(z).

In some embodiments, a metal complex has a structureL_(p)-M-(L_(I))_(m), where L_(p)-M is selected from the group consistingof:

In other embodiments, the permanent ligand set comprises a porphyrinring and L_(p)-M has the structure:

wherein:

-   -   M, L_(I), R^(c), and R^(d) are as defined above and any two        adjacent R^(c) or R^(d) groups can be taken together to form one        or more rings optionally substituted with one or more R²⁰ groups

In certain embodiments where the permanent ligand set comprises aporphyrin ring, M is a metal atom selected from the group consisting of:cobalt; chromium; aluminum; titanium; ruthenium, and manganese.

As noted above, in some embodiments herein, the permanent ligand set maycomprise a plurality of discrete ligands. In certain embodiments thepermanent ligand set includes two bidentate ligands. In certainembodiments, such bidentate ligands may have the structure

where R^(d) and R¹¹ are as defined hereinabove. Metal complexes havingtwo such ligands may adopt one of several geometries, and the presentdisclosure encompasses complex having any of the possible geometries, aswell as mixtures of two or more geometrical isomers.

In certain embodiments, metal complexes including two bidentate ligandsmay have structures selected from the group consisting of:

where each

represents a ligand:

I.a.3 Initiating Ligands

In addition to a metal atom and a permanent ligand set describedhereinabove, metal complexes suitable for polymerization systems of thepresent invention optionally include one or more initiating ligands-L_(I). In some embodiments, these ligands act as polymerizationinitiators and become a part of a growing polymer chain. In certainembodiments, there is one initiating ligand present (i.e. m=1). In otherembodiments, there are two initiating ligands present (i.e. m=2). Incertain embodiments, an initiating ligand may be absent (i.e. m=0). Incertain embodiments, a metal complex may be added to a reaction mixturewithout an initiating ligand, but may form a species in situ thatincludes one or two initiating ligands.

In certain embodiments, -L_(I) is any anion. In certain embodiments,-L_(I) is a nucleophile. In some embodiments, initiating ligands -L_(I)are nucleophiles capable of ring-opening an epoxide. In someembodiments, a polymerization initiator L_(I) is selected from the groupconsisting of: azide, halides, alkyl sulfonates, carboxylates,alkoxides, and phenolates.

In some embodiments, initiating ligands include, but are not limited to,—OR^(x), —SR^(x), —OC(O)R^(x), —OC(O)OR^(x), —OC(O)N(R^(x))₂,—NR^(x)C(O)R^(x), —CN, halo (e.g., —Br, —I, —Cl), —N₃, and —OSO₂R^(x)wherein each R^(x) is, independently, selected from hydrogen, optionallysubstituted aliphatic, optionally substituted heteroaliphatic,optionally substituted aryl and optionally substituted heteroaryl andwhere two R^(x) groups can be taken together to form an optionallysubstituted ring optionally containing one or more additionalheteroatoms.

In certain embodiments, -L_(I) is —OC(O)R^(x), wherein R^(x) is selectedfrom optionally substituted aliphatic, fluorinated aliphatic, optionallysubstituted heteroaliphatic, optionally substituted aryl, fluorinatedaryl, and optionally substituted heteroaryl.

In certain embodiments, -L_(I) is —OC(O)R^(x), wherein R^(x) isoptionally substituted aliphatic. In certain embodiments, -L_(I) is—OC(O)R^(x), wherein R^(x) is optionally substituted alkyl orfluoroalkyl. In certain embodiments, -L_(I) is —OC(O)CH₃ or —OC(O)CF₃.

Furthermore, in certain embodiments, -L_(I) is —OC(O)R^(x), whereinR^(x) is optionally substituted aryl, fluoroaryl, or heteroaryl. Incertain embodiments, -L_(I) is —OC(O)R^(x), wherein R^(x) is optionallysubstituted aryl. In certain embodiments, -L_(I) is —OC(O)R^(x), whereinR^(x) is optionally substituted phenyl. In certain embodiments, -L_(I)is —OC(O)C₆H₅ or —OC(O)C₆F₅.

In certain embodiments, -L_(I) is —OR^(x), wherein R^(x) is selectedfrom optionally substituted aliphatic, optionally substitutedheteroaliphatic, optionally substituted aryl, and optionally substitutedheteroaryl.

For example, in certain embodiments, -L_(I) is —OR^(x), wherein R^(x) isoptionally substituted aryl. In certain embodiments, -L_(I) is —OR^(x),wherein R^(x) is optionally substituted phenyl. In some embodiments,-L_(I) is a 2,4-dinitrophenolate anion. In certain embodiments, -L_(I)is —OC₆H₅.

In certain embodiments, -L_(I) is halo. In certain embodiments, -L_(I)is —Br. In certain embodiments, -L_(I) is —Cl. In certain embodiments,-L_(I) is —I.

In certain embodiments, -L_(I) is —O(SO₂)R^(x). In certain embodiments-L_(I) is —OTs. In certain embodiments -L_(I) is —OSO₂Me. In certainembodiments -L_(I) is —OSO₂CF₃.

In some embodiments, metal complexes L_(p)-M-(L_(I))_(m), include one ormore initiating ligands -L_(I) characterized in that each ligand iscapable of initiating two or more polymer chains. In some embodiments,the initiating ligand is any of the molecules described above as beingsuitable as chain transfer agents. In certain embodiments, an initiatingligand is an anion derived from any of the chain transfer agentsdescribed hereinabove.

In some embodiments, a polymerization initiator -L_(I) comprises acompound of the formula -Q′-A′-(Z′)_(n), wherein:

-   -   -Q′- is a carboxy or alkoxy group,    -   -A′- is a covalent bond or a multivalent moiety,    -   each Z′ is independently a functional group that can initiate a        polymer chain, and    -   n is an integer between 1 and 10 inclusive.

In certain embodiments wherein a polymerization initiator comprises acompound having the formula -Q′-A′(Z′)_(n), each —Z′, is a functionalgroup independently selected from the group consisting of: —OH, —C(O)OH,—C(OR^(y))OH, —OC(R^(y))OH, —NHR^(y), —NHC(O)R^(y), —NHC═NR^(y);—NR^(y)C═NH; —NR^(y)C(NR^(y) ₂)═NH; —NHC(NR^(y) ₂)═NR^(y);—NHC(O)OR^(y), —NHC(O)NR^(y) ₂, —C(O)NHR^(y), —C(S)NHR^(y),—OC(O)NHR^(y), —OC(S)NHR^(y), —SH, —C(O)SH, —B(OR^(y))OH,—P(O)_(a)(R^(y))_(b)(OR^(y))_(c)(OH)_(d),—OP(O)_(a)(R^(y))_(b)(OR^(y))_(c)(OH)_(d), —N(R^(y))OH, —ON(R^(y))H;═NOH, ═NN(R^(y))H, where each occurrence of R^(y) is independently —H,or an optionally substituted radical selected from the group consistingof C₁₋₂₀ aliphatic, C₁₋₂₀ heteroaliphatic, 3- to 12-memberedheterocyclic, and 6- to 12-membered aryl, a and b are each independently0 or 1, c is 0, 1 or 2, d is 0 or 1, and the sum of a, b, and c is 1 or2; and

-   -   -A′- is selected from the group consisting of: a) C₂-C₂₀        aliphatic b) a C₃-C₂₀ carbocycle; c) a 3- to 12-membered        heterocycle; d) a saccharide; e) an oligosaccharide; f) a        polysaccharide; and g) a polymer chain, wherein any of (a)        through (g) are optionally substituted with one or more R²⁰        groups.

In certain embodiments wherein a polymerization initiator comprises acompound having the formula -Q′-A′-(Z′)_(n), each —Z′, is independentlyselected from the group consisting of: —OH; and —C(O)OH—.

In some embodiments, -A′- is a covalent bond.

In certain embodiments wherein a polymerization initiator comprises acompound having the formula -Q′-A′-(Z′)_(n), -A′- is a C₂₋₂₀ aliphaticgroup, and n is an integer from 1 to 5.

In certain embodiments wherein a polymerization initiator comprises acompound having the formula -Q′-A′(Z′)_(n), -A′- is a C₂₋₁₂ aliphaticgroup, and n is an integer from 1 to 3.

In certain embodiments wherein a polymerization initiator comprises acompound having the formula -Q′-A′(Z′)_(n), Q′ is —OC(O)—; -A′- is aC₂₋₂₀ aliphatic group; Z′ is —OH; and n is an integer from 1 to 3.

In certain embodiments, where a polymerization initiator has more thanone site capable of coordinating with a metal atom, a singlepolymerization initiator may be shared by multiple metal complexes (eachmetal complex including at one metal atom and a permanent ligand set).For example, when L_(I) is a diacid, each carboxyl group of the diacidmay be coordinated to a metal atom of a separate metal complex (i.e. adimeric or pseudodimeric complex having a formulaL_(p)-M-O₂C-A′-CO₂-M-L_(p), where A′, M, and L_(p) are as definedpreviously). Similarly, a triacid may be coordinated to one two or threemetal centers, or a hydroxy acid, a dialkoxide, amino acid or otherpolyfunctional compound can coordinate with two or more L_(p)-M groups.

In certain embodiments, an initiating ligand is a polycarboxylic acidhaving 2 to 4 carboxyl groups. In certain embodiments, an initiatingligand is a C₂₋₂₀ diacid. In certain embodiments, an initiating ligandis selected from the group consisting of I-1 through I-24:

In certain embodiments, an initiating ligand having a plurality ofpolymer initiation sites may be a hydroxy acid. In certain embodiments,a hydroxy acid is selected from the group consisting of:

In certain embodiments, a polymerization initiator having a plurality ofpolymer initiation sites is a polyhydric phenol derivative. In certainembodiments, a polymerization initiator is selected from the groupconsisting of:

In some embodiments, an initiating ligand is a polyalcohol. In certainembodiments, a polyalcohol is a diol. Suitable diols include but are notlimited to: 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol,1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol,2,2-dimethylpropane-1,3-diol, 2-butyl-2-ethylpropane-1,3-diol,1,5-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol,1,12-dodecanediol, 2,2,4,4-tetramethylcyclobutane-1,3-diol,1,3-cyclopentanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol,1,4-cyclohexanedimethanol, and 1,4-cyclohexanediethanol.

In some embodiments, an initiating ligand is an alkoxide derived from acompound selected from the group consisting of: diethylene glycol,triethylene glycol, tetraethylene glycol, pentaethylene glycol, higherpoly(ethylene glycol), dipropylene glycol, tripropylene glycol, andhigher poly(propylene glycol). In some embodiments, higher poly(ethyleneglycol) compounds are those having number average molecular weights offrom 220 to about 2000 g/mol. In some embodiments, higher poly(propyleneglycol) compounds are those having number average molecular weights offrom 234 to about 2000 g/mol.

In some embodiments, suitable diols include 4,4′-(1-methylethylidene)bis[cyclohexanol], 2,2′-methylenebis[phenol], 4,4′-methylenebis[phenol],4,4′-(phenylmethylene)bis[phenol], 4,4′-(diphenylmethylene)bis[phenol],4,4′-(1,2-ethanediyl)bis[phenol], 4,4′-(1,2-cyclohexanediyl)bis[phenol],4,4′-(1,3-cyclohexanediyl)bis[phenol],4,4′-(1,4-cyclohexanediyl)bis[phenol], 4,4′-ethylidenebis[phenol],4,4′-(1-phenylethylidene)bis[phenol], 4,4′-propylidenebis[phenol],4,4′-cyclohexylidenebis[phenol], 4,4′-(1-methylethylidene)bis[phenol],4,4′-(1-methylpropylidene)bis[phenol],4,4′-(1-ethylpropylidene)bis[phenol], 4,4′-cyclohexylidenebis[phenol],4,4′-(2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyldi-2,1-ethanediyl)bis[phenol],1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol,4,4′-[1,3-phenylenebis(1-methylethylidene)]bis[phenol],4,4′-[1,4-phenylenebis(1-methylethylidene)]bis[phenol], phenolphthalein,4,4′-(1-methylidene)bis[2-methylphenol],4,4′-(1-methylethylidene)bis[2-(1-methylethyl)phenol],2,2′-methylenebis[4-methyl-6-(1-methylethyl)phenol],

In some embodiments, a polyol is a triol. Suitable triols may include,but are not limited to: aliphatic triols having a molecular weight lessthan 500 such as trimethylolethane; trimethylolpropane; glycerol;1,2,4-butanetriol; 1,2,6-hexanetriol; tris(2-hydroxyethyl)isocyanurate;hexahydro-1,3,5-tris(hydroxyethyl)-s-triazine;6-methylheptane-1,3,5-triol; polypropylene oxide triol; and polyestertriols.

In certain embodiments, a polyol is a tetraol. Examples of suitabletetraols include, but are not limited to: erythritol, pentaerythritol;2,2′-dihydroxymethyl-1,3-propanediol; and2,2′-(oxydimethylene)bis-(2-ethyl-1,3-propanediol).

In certain embodiments, a metal coordination complex is selected fromthe group consisting of:

In some embodiments, a metal coordination complex is selected fromcompounds of formulae XLIX through LIV:

In some embodiments, polymerization systems of the present inventionfurther include at least one co-catalyst. In some embodiments, aco-catalyst is selected from the group consisting of: amines,guanidines, amidines, phosphines, nitrogen-containing heterocycles,ammonium salts, phosphonium salts, arsonium salts, bisphosphine ammoniumsalts, and a combination of any two or more of the above.

In embodiments where the co-catalyst is an ‘onium’ salt, there isnecessarily an anion present to balance the charge of the salt. Incertain embodiments, this is any anion. In certain embodiments, theanion is a nucleophile. In some embodiments, the anion is a nucleophilecapable of ring-opening an epoxide. In some embodiments, the anion isselected from the group consisting of: azide, halides, alkyl sulfonates,carboxylates, alkoxides, and phenolates.

In some embodiments, ionic co-catalyst include anions selected from thegroup consisting of: —OR^(x), —SR^(x), —OC(O)R^(x), —OC(O)OR^(x),—OC(O)N(R^(x))₂, —NR^(x)C(O)R^(x), —CN, halo (e.g., —Br, —I, —Cl), —N₃,and —OSO₂R^(x) wherein each R^(x) is, independently, selected fromhydrogen, optionally substituted aliphatic, optionally substitutedheteroaliphatic, optionally substituted aryl and optionally substitutedheteroaryl and where two R^(x) groups can be taken together to form anoptionally substituted ring optionally containing one or more additionalheteroatoms.

In certain embodiments, a co-catalyst anion is —OC(O)R^(x), whereinR^(x) is selected from optionally substituted aliphatic, fluorinatedaliphatic, optionally substituted heteroaliphatic, optionallysubstituted aryl, fluorinated aryl, and optionally substitutedheteroaryl.

In certain embodiments, a co-catalyst anion is —OC(O)R^(x), whereinR^(x) is optionally substituted aliphatic. In certain embodiments, aco-catalyst anion is —OC(O)R^(x), wherein R^(x) is optionallysubstituted alkyl and fluoroalkyl. In certain embodiments, a co-catalystanion is —OC(O)CH₃ or —OC(O)CF₃.

Furthermore, in certain embodiments, a co-catalyst anion is —OC(O)R^(x),wherein R^(x) is optionally substituted aryl, fluoroaryl, or heteroaryl.In certain embodiments, a co-catalyst anion is —OC(O)R^(x), whereinR^(x) is optionally substituted aryl. In certain embodiments, aco-catalyst anion is —OC(O)R^(x), wherein R^(x) is optionallysubstituted phenyl. In certain embodiments, a co-catalyst anion is—OC(O)C₆H₅ or —OC(O)C₆F₅.

In certain embodiments, a co-catalyst anion is —OR^(x), wherein R^(x) isselected from optionally substituted aliphatic, optionally substitutedheteroaliphatic, optionally substituted aryl, and optionally substitutedheteroaryl.

For example, in certain embodiments, a co-catalyst anion is —OR^(x),wherein R^(x) is optionally substituted aryl. In certain embodiments, aco-catalyst anion is —OR^(x), wherein R^(x) is optionally substitutedphenyl. In certain embodiments, a co-catalyst anion is —OC₆H₅ or—OC₆H₂(2,4-NO₂).

In certain embodiments, a co-catalyst anion is halo. In certainembodiments, a co-catalyst anion is —Br. In certain embodiments, aco-catalyst anion is —Cl. In certain embodiments, a co-catalyst anion is—I.

In certain embodiments, a co-catalyst anion is —O(SO₂)R^(x). In certainembodiments a co-catalyst anion is —OTs. In certain embodiments aco-catalyst anion is —OSO₂Me. In certain embodiments a co-catalyst anionis —OSO₂CF₃. In some embodiments, a co-catalyst anion is a2,4-dinitrophenolate anion.

In certain embodiments, polymerization systems of the present inventioninclude a cationic co-catalyst having a counterion characterized in thatthe counterion is capable of initiating polymerization at two or moresites. In some embodiments, a counterion is any of the moleculesdescribed above as being suitable as initiating ligands (L_(I)). Incertain embodiments, an anion is derived from any of the chain transferagents described hereinabove.

In some embodiments, an anion of the ionic co-catalyst comprises ananion of the formula ⁻Q′-A′(Z′)_(n), wherein:

-   -   ⁻Q′- is a carboxy or alkoxy group,    -   -A′- is a covalent bond or a multivalent moiety,    -   each Z′ is independently a functional group that can initiate a        polymer chain, and    -   n is an integer between 1 and 10 inclusive,

In certain embodiments, where an anion of an ionic co-catalyst is apolyfunctional compound, it is possible for a polyfunctional compound tobe counterion to more than one cationic co-catalyst, or to be associatedwith both a co-catalyst cation and a metal complex. For example, if aco-catalyst is an ammonium salt and the counterion is a diacid, thediacid may be doubly deprotonated and maybe associated with two ammoniumcations: N⁺R₄ ^(−O) ₂C-A′-CO₂ ⁻N⁺R₄. Similarly, two PPN+ cations may beassociated with a single diacid. Alternatively, the diacid may beassociated with both a co-catalytic cation and a metal complex: N⁺R₄⁻O₂C-A′-CO₂ ⁻M⁺-L_(p). It will be apparent to the skilled artisan thatmany such variations are possible and it will also be understood thatthe ionic compounds and coordination complexes described may be inequilibrium. As such that the active species present at different timesduring the polymerization reactions may change. In some instances knownmethods of producing mono salts of polyfunctional compounds can be usedto influence the stoichiometry of the polymerization system.

In certain embodiments, anions present to balance the charge of cationicco-catalysts, and the initiating ligand on the metal complex areselected to be the same compound. In certain embodiments, an initiatingligand, a counterion present on a cationic co-catalyst, and a chaintransfer agent are chosen to be the same molecule. For instance, in oneexample of this embodiment if glycolic acid were employed as the chaintransfer agent, the metal complex would be chosen to include glycolateas the initiating ligand L_(I) and a cationic co-catalyst including aglycolate counterion (such as tetrabutylammonium glycolate) could beemployed as the co-catalyst. Such embodiments of the present inventionprovide polycarbonate polyol compositions that are highly homogenoussince virtually all chains have the same chemical makeup. The details ofthese compositions and methods to produce them are described in moredetail hereinbelow.

Ic. Stoichiometry of the Polymerization Systems

Having described in detail each of the components of the polymerizationsystem, we turn now to the relative ratios of those components. Incertain embodiments, a metal complex L_(p)-M-(L_(I))_(m) and a chaintransfer agent Y-A-(Y)_(n) are present in a defined ratio selected tomaximize conversion of the epoxide monomers while achieving the desiredmolecular weight polycarbonate polyol. In embodiments, where aco-catalyst is present, the ratios between a metal complex, aco-catalyst and a chain transfer agent are selected to maximizeconversion of the epoxide monomers while achieving the desired molecularweight polycarbonate polyol.

In some embodiments, a metal complex and a chain transfer agent arepresent in a molar ratio ranging from about 1:10 to about 1:1000. Incertain embodiments, the ratio is between about 1:50 and about 1:500. Incertain embodiments, the ratio is between about 1:50 and about 1:250. Incertain embodiments, the ratio is between about 1:20 and about 1:100. Incertain embodiments, the ratio is between about 1:100 and about 1:250.In some embodiments, a metal complex and a chain transfer agent arepresent in a molar ratio greater than 1:1000. In some embodiments, ametal complex and a chain transfer agent are present in a molar ratioless than 1:1000.

In some embodiments, a metal complex and a co-catalyst are present in amolar ratio ranging from about 0.1:1 to about 1:10. In certainembodiments, the ratio is from about 0.5:1 to about 5:1. In otherembodiments, the ratio is from about 1:1 to about 4:1. In certainembodiments the ratio between the metal complex and the co-catalyst isabout 1:1. In other embodiments, the molar ratio between a metal complexand a co-catalyst is about 1:2.

II. Polycarbonate Polyol Compositions

As described above, there have not been methods heretofore available toproduce aliphatic polycarbonate polyol resins combining the features ofhigh carbonate linkage content, a high percentage of hydroxyl end groupsand low molecular weight (e.g. less than about 20 kg/mol). In oneaspect, the present invention encompasses these novel materials.

In some embodiments, the present invention encompasses epoxide CO₂copolymers with a molecular weight number between about 400 and about20,000 characterized in that the polymer chains have a carbonate contentof >90%, and at least 90% of the end groups are hydroxyl groups.

In certain embodiments, the carbonate linkage content of thepolycarbonate chains of epoxide CO₂ copolymers of the present inventionis at least 90%. In some embodiments greater than 92% of linkages arecarbonate linkages. In certain embodiments, at least 95% of linkages arecarbonate linkages. In certain embodiments, at least 97% of linkages arecarbonate linkages. In some embodiments, greater than 98% of linkagesare carbonate linkages in some embodiments at least 99% of linkages arecarbonate linkages. In some embodiments essentially all of the linkagesare carbonate linkages (i.e. there are essentially only carbonatelinkages detectable by typical methods such as ¹H or ¹³C NMRspectroscopy).

In certain embodiments, the ether linkage content of the polycarbonatechains of epoxide CO₂ copolymers of the present invention is less than10%. In some embodiments, less than 8% of linkages are ether linkages.In certain embodiments, less than 5% of linkages are ether linkages. Incertain embodiments, no more than 3% of linkages are ether linkages. Insome embodiments, fewer than 2% of linkages are ether linkages in someembodiments less than 1% of linkages are ether linkages. In someembodiments essentially none of the linkages are ether linkages (i.e.there are essentially no ether bonds detectable by typical methods suchas ¹H or ¹³C NMR spectroscopoy).

In some embodiments, the epoxide CO₂ copolymers of the present inventionhave average molecular weight numbers ranging from about 400 to about400,000 g/mol. In some embodiments, the epoxide CO₂ copolymers of thepresent invention have average molecular weight numbers ranging fromabout 400 to about 20,000 g/mol. In some embodiments, the copolymershave an Mn between about 500 and about 5,000 g/mol. In otherembodiments, the copolymers have an Mn between about 800 and about 4,000g/mol. In some embodiments, the copolymers have an Mn between about1,000 and about 3,000 g/mol. In some embodiments, the copolymers have anMn of about 1,000 g/mol. In some embodiments, the copolymers have an Mnof about 2,000 g/mol. In some embodiments, the copolymers have an Mn ofabout 3,000 g/mol. In certain embodiments, epoxide CO₂ copolymers of theinvention have about 10 to about 200 repeat units. In other embodiments,the copolymers have about 20 to about 100 repeat units.

In some embodiments, the CO₂ epoxide copolymers of the present inventionare formed from CO₂ and one type of epoxide. In other embodiments, thecopolymers incorporate two or more types of epoxide. In someembodiments, the copolymers predominantly incorporate one epoxide withlesser amounts of one or more additional epoxides. In certainembodiments where two or more epoxides are present, the copolymer israndom with respect to the position of the epoxide moieties within thechain. In other embodiments where two or more epoxides are present, thecopolymer is a tapered copolymer with respect to the incorporation ofdifferent epoxides. In some embodiments where two or more epoxides arepresent, the copolymer is a block copolymer with respect to theincorporation of different epoxides.

In certain embodiments, the polymer chains may contain embeddedpolymerization initiators or may be a block-copolymer with anon-polycarbonate segment. In certain examples of these embodiments, thestated total carbonate content of the polymer chain may be lower thanthe stated carbonate content limitations described above. In thesecases, the carbonate content refers only to the epoxide CO₂ copolymericportions of the polymer composition. In other words, a polymer of thepresent invention may contain a polyester, polyether orpolyether-polycarbonate moiety embedded within or appended to it. Thenon-carbonate linkages in such moieties are not included in thecarbonate and ether linkage limitations described above.

In certain embodiments, polycarbonate polyols of the present inventionare further characterized in that they have narrow polydispersity. Incertain embodiments, the PDI of the provided polymer compositions isless than 2. In some embodiments, the PDI is less than 1.5. In otherembodiments, the PDI is less than about 1.4. In certain embodiments, thePDI is less than about 1.2. In other embodiments, the PDI is less thanabout 1.1. In certain embodiments, the polycarbonate polyol compositionsare further characterized in that they have a unimoldal molecular weightdistribution.

In certain embodiments, the polycarbonate polyols of the presentinvention contain repeat units derived from epoxides that are not C2symmetric. In these cases, the epoxide can be incorporated into thegrowing polymer chain in one of several orientations. The regiochemistryof the enchainment of adjacent monomers in such cases is characterizedby the head-to-tail ratio of the composition. As used herein the term“head-to-tail” refers to the regiochemistry of the enchainment of asubstituted epoxide in the polymer chain as shown in the figure belowfor propylene oxide:

In certain embodiments the disclosure encompasses polycarbonate polyolcompositions characterized in that, on average, more than about 80% oflinkages between adjacent epoxide monomer units are head-to-taillinkages. In certain embodiments, on average, more than 85% of linkagesbetween adjacent epoxide monomer units are head-to-tail linkages. Incertain embodiments, on average, more than 90% of linkages betweenadjacent epoxide monomer units are head-to-tail linkages. In certainembodiments, more than 95% of linkages between adjacent epoxide monomerunits are head-to-tail linkages. In certain embodiments, more than 99%of linkages between adjacent epoxide monomer units are head-to-taillinkages.

In certain embodiments, the polycarbonate polyols of the presentinvention contain repeat units derived from epoxides that contain achiral center. In these cases, the epoxide can be incorporated into thegrowing polymer chain in defined orientations relative to adjacentmonomer units. In certain embodiments, the adjacent stereocenters arearranged randomly within the polymer chains. In certain embodiments, thepolycarbonate polyols of the present invention are atactic. In otherembodiments, more than about 60% of adjacent monomer units have the samestereochemistry. In certain embodiments, more than about 75% of adjacentmonomer units have the same stereochemistry. In certain embodiments,more than about 85% of adjacent monomer units have the samestereochemistry. In certain embodiments, more than about 95% of adjacentmonomer units have the same stereochemistry. In certain embodiments thepolycarbonate polyols of the present invention are isotactic. In otherembodiments, more than about 60% of adjacent monomer units have theopposite stereochemistry. In certain embodiments, more than about 75% ofadjacent monomer units have the opposite stereochemistry. In certainembodiments, more than about 85% of adjacent monomer units have theopposite stereochemistry. In certain embodiments, more than about 95% ofadjacent monomer units have the opposite stereochemistry. In certainembodiments the polycarbonate polyols of the present invention aresyndiotactic.

In certain embodiments, where a chiral epoxide is incorporated into thepolycarbonate polyol compositions of the present invention, the polymersare enantio-enriched. In other embodiments, where a chiral epoxide isincorporated into the polycarbonate polyol compositions of the presentinvention, the polymers are not enantio-enriched.

In certain embodiments, the epoxide monomers incorporated intopolycarbonate polyols of the present invention have a structure:

-   -   where, R²¹, R²², R²³, and R²⁴, are each independently selected        from the group consisting of: —H; and an optionally substituted        group selected from C₁-₃₀ aliphatic; C₆₋₁₄ aryl; 3- to        12-membered heterocycle, and 5- to 12-membered heteroaryl, where        any two or more of R²¹, R²², R²³, and R²⁴ can be taken together        with intervening atoms to form one or more optionally        substituted 3- to 12-membered rings, optionally containing one        or more heteroatoms.

In certain embodiments, the polycarbonate polyols of the presentinvention incorporate one or more epoxides selected from the groupconsisting of:

wherein each R^(x) is, independently, selected from optionallysubstituted aliphatic, optionally substituted heteroaliphatic,optionally substituted aryl fluoroalkyl, and optionally substitutedheteroaryl.

In certain embodiments, polycarbonate polyols of the present inventioncomprise poly(ethylene carbonate). In other embodiments, polycarbonatepolyols of the present invention comprise poly(propylene carbonate). Inother embodiments, polycarbonate polyols of the present inventioncomprise poly(cyclohexene carbonate). In other embodiments,polycarbonate polyols of the present invention comprisepoly(epichlorohydrin carbonate). In certain embodiments, polycarbonatepolyols of the present invention incorporate a glycidyl ether orglycidyl ester. In certain embodiments, polycarbonate polyols of thepresent invention incorporate phenyl glycidyl ether. In certainembodiments, polycarbonate polyols of the present invention incorporatet-butyl glycidyl ether.

In some embodiments, polycarbonate polyols of the present inventioncomprise poly(propylene-co-ethylene carbonate). In certain embodiments,polycarbonate polyols of the present invention comprise poly(propylenecarbonate) incorporating from about 0.1 to about 10% of a C₄-C₃₀epoxide. In certain embodiments, polycarbonate polyols of the presentinvention comprise poly(propylene carbonate) incorporating from about0.1 to about 10% of a glycidyl ether. In certain embodiments,polycarbonate polyols of the present invention comprise poly(propylenecarbonate) incorporating from about 0.1 to about 10% of a glycidylester. In certain embodiments, polycarbonate polyols of the presentinvention comprise poly(ethylene carbonate) incorporating from about 0.1to about 10% of a glycidyl ether. In certain embodiments, polycarbonatepolyols of the present invention comprise poly(ethylene carbonate)incorporating from about 0.1 to about 10% of a glycidyl ester. Incertain embodiments, polycarbonate polyols of the present inventioncomprise poly(ethylene carbonate) incorporating from about 0.1 to about10% of a C₄-C₃₀ epoxide.

In certain embodiments, epoxide monomers incorporated into polycarbonatepolyols of the present invention include epoxides derived from naturallyoccurring materials such as epoxidized resins or oils. Examples of suchepoxides include, but are not limited to: Epoxidized Soybean Oil;Epoxidized Linseed Oil; Epoxidized Octyl Soyate; Epoxidized PGDO; MethylEpoxy Soyate; Butyl Epoxy Soyate; Epoxidized Octyl Soyate; Methyl EpoxyLinseedate; Butyl Epoxy Linseedate; and Octyl Epoxy Linseedate. Theseand similar materials are available commercially from Arkema Inc. underthe trade name Vikoflex®. Examples of such commerically availableVikoflex® materials include Vikoflex 7170 Epoxidized Soybean Oil,Vikoflex 7190 Epoxidized Linseed, Vikoflex 4050 Epoxidized Octyl Soyate,Vikoflex 5075 Epoxidized PGDO, Vikoflex 7010 Methyl Epoxy Soyate,Vikoflex 7040 Butyl Epoxy Soyate, Vikoflex 7080 Epoxidized Octyl Soyate,Vikoflex 9010 Methyl Epoxy Linseedate, Vikoflex 9040 Butyl EpoxyLinseedate, and Vikoflex 9080 Octyl Epoxy Linseedate. In certainembodiments, the polycarbonate polyols of the present inventionincorporate epoxidized fatty acids:

In certain embodiments of the present invention, polycarbonate polyolsof the present invention incorporate epoxides derived from alphaolefins. Examples of such epoxides include, but are not limited to thosederived from C₁₀ alpha olefin, C₁₂ alpha olefin, C₁₄ alpha olefin, C₁₆alpha olefin, C₁₈ alpha olefin, C₂₀-C₂₄ alpha olefin, C₂₄ ⁻C₂₈ alphaolefin and C₃₀₊ alpha olefins. These and similar materials arecommercially available from Arkema Inc. under the trade name Vikolox®.Commerically available Vikolox® materials include those depicted inTable 4, below. In certain embodiments, provided aliphaticpolycarbonates derived from alpha olefins are heteropolymersincorporating other simpler epoxide monomers including, but not limitedto: ethylene oxide, propylene oxide, butylene oxide, hexene oxide,cyclopentene oxide and cyclohexene oxide. These heteropolymers caninclude random co-polymers, tapered copolymers and block copolymers.

TABLE 4 Trade Name Formula Minimum Oxirane Vikolox 10 C₁₀H₂₀O 9.0%Vikolox 12 C₁₂H₂₄O 7.8% Vikolox 14 C₁₄H₂₈O 6.8% Vikolox 16 C₁₆H₃₂O 6.0%Vikolox 18 C₁₈H₃₆O 5.4% Vikolox 20-24 C₂₀₋₂₄H₄₀₋₄₈O 4.4% Vikolox 24-28C₂₄₋₂₈H₄₈₋₅₆O 3.25%  Vikolox 30+ C₃₀₊H₆₀O 2.25% 

In certain embodiments, the present disclosure encompasses aliphaticpolycarbonate compositions comprising a plurality of polymer chaintypes. In certain embodiments these different chain types are derivedfrom more than one type of initiating moiety. These compositions aredescribed in more detail below. In each case, the polycarbonate chainscontain one or more polymeric units arising from the alternatingcopolymerization of CO₂ and one or more epoxides. In the descriptionsthat follow of the several chain types that may be present in thecompositions of the present invention, these alternating copolymericunits are denoted -T, where each -T is a polycarbonate chain having aformula independently selected from the group consisting of:

wherein:

-   -   E is an optionally substituted C₂ unit derived from an epoxide,        where E may represent a monomer unit derived from one type of        epoxide, or from a mixture of two or more types of epoxide, and    -   p ranges from about 5 to about 10,000.

In some embodiments of polymers encompassed by the present invention,-E- is:

where R²¹, R²², R²³, and R²⁴ are as defined above.

In certain embodiments, -E- is selected from the group consisting of:

and mixtures of any two or more of these.

In certain embodiments, -E- includes units derived from naturallyoccurring materials such as epoxidized resins or oils. In certainembodiments, -E- includes units derived C₁₂₋₃₀ alpha olefins.

In some embodiments, -E- consists predominantly of —CH₂CH₂— unitsderived from ethylene oxide. In certain embodiments, -E- includes unitsderived from ethylene oxide in combination with amounts of more complex-E- groups derived from other epoxides.

In other embodiments, -E- consists predominantly of —CH₂CH(CH₃)— groupsderived from propylene oxide. In certain embodiments, -E- includes unitsderived from propylene oxide in combination -E- groups derived ethyleneoxide. In certain embodiments, -E- includes units derived from propyleneoxide in combination with lesser amounts of more complex -E- groupsderived from other epoxides.

In certain embodiments, the polycarbonate polyol compositions describedabove include mixtures of several chain types. In general, these chaintypes may be divided into two categories: namely, a first categoryincluding chains denoted P¹ having two or more —OH end groups and asecond category of chains denoted P² having only one —OH end group perchain. As described above, in some embodiments compositions of thepresent invention have at least 90% of the polymer chain endsterminating with —OH groups. As such, chains of the first categorygenerally make up a predominance of the chains present in thecompositions.

Polymer chains in a given composition may arise from each of severaldifferent chain-initiating moieties present in a reaction mixture. Incertain cases each of these chain types will have a distinct structurethat differentiates it from other chain types present in the mixturethat derive from other chain initiating moieties. The structures of eachof several chain types are described below, and the ratios in whichthese components may be present are then described.

The aliphatic polycarbonate compositions of the present inventioninclude polymer chains derived from the chain transfer agents describedhereinabove. In certain embodiments, these polymer chains are denotedP¹. In some embodiments, where the chain transfer agent has a formulaY-A-(Y)_(n), as described above, polymer chains of type P¹ have theformula T-Y-A-(Y-T)_(n), wherein Y, A, and n are as defined above in thedescription of the chain transfer agents, and each -T is an aliphaticpolycarbonate chain covalently bound to a Y group, where -T is asdefined above.

Chains of type P¹ may also derive from the polyfunctional initiatingligands L_(I) described hereinabove. In certain embodiments, where theinitiating ligand has a formula Q′-A′-(Z′)_(n), as described above, suchchains have the formula T-Q′-A′(Z′-T)_(n), wherein Q′, A′, Z′, and n areas defined above in the description of the initiating ligands, and each-T is an aliphatic polycarbonate chain covalently bound to a Q′ or Z′group, where -T is as defined above.

Additionally, chains of type P¹ may arise from an anion present on aco-catalyst. In certain embodiments, where the anion has a formulaQ′-A′-(Z′)_(n) as described above, such chains have the formulaT-Q′-A′(Z′-T)_(n), wherein Q′, A′, Z′, and n are as defined above in thedescription of the co-catalyst anions, and each -T is an aliphaticpolycarbonate chain covalently bound to a Q′ or Z′ group, where -T is asdefined above.

An additional category of P^(i) chains may arise from water present inthe reaction mixtures. In some circumstances, under polymerizationconditions the water will ring-open an epoxide leading to formation of aglycol corresponding to one or more epoxides present in the reactionmixture. In certain embodiments, this glycol (or mixture of glycols ifmore than one type of epoxide is present) will lead to formation ofchains of type P^(1a) having the structure:

-   -   wherein -E- is an optionally substituted C₂ unit derived from an        epoxide, where E may represent a monomer unit derived from a        single type of epoxide or from a mixture of two or more types of        epoxide, and

p ranges from about 5 to about 10,000.

In some embodiments, each of these sources of chains P¹ may have adifferent structure and the compositions may include several types of P¹chain (e.g. type P¹ derived from the chain transfer agent, type P^(1′)derived from polyfunctional initiating ligands, and type P^(1″) derivedfrom polyfunctional anions present on a co-catalyst). In certainembodiments, the chain transfer agent, initiating ligand, andco-catalyst anions may have the same structure (or be ionic forms of thesame structure). In these instances, the polymer compositions maycomprise only one type of P¹ chain, or if water is present a mixture ofa single type of P¹ chain along with some amount of P^(1a). In certainembodiments, a glycol corresponding to an epoxide present in thereaction mixture may be used as a chain transfer agent in which case,polymer chains P¹ arising from the chain transfer agent and P^(1a)arising from water will be indistinguishable. In certain otherembodiments, water may be rigorously excluded from the polymerizationmixture in which case chains of type P^(1a) will be substantiallyabsent.

Additionally, in certain embodiments polymer compositions of the presentinvention include polymer chains of type P². These chains have only oneOH end group. Chains of type P² may arise from monofunctional initiatingligands present on the metal complexes or from monofunctional anionspresent on ionic co-catalysts. In certain cases, such chains may alsoarise from spurious sources such as alcohols or halide ions present asimpurities in the reaction mixtures. In certain embodiments, chains oftype P² have a formula selected from the group consisting of:

wherein:

-   -   X is a bound form of an anion capable of initiating one polymer        chain;    -   E is an optionally substituted C₂ unit derived from an epoxide,        where E may represent a monomer unit derived from one type of        epoxide, or from a mixture of two or more types of epoxide, and    -   p ranges from about 5 to about 10,000.

In certain embodiments of polymer chains of type P², X comprises ahalogen atom, an azide, an ester group, an ether group, or a sulfonicester group.

In some embodiments, polymer compositions of the present invention arecharacterized in that at least 90% of the chains ends are —OH. Incertain embodiments, at least 90% of the chains in a polymer compositionare of type P¹. In certain embodiments, the chains of type P¹ areessentially all the same. In other embodiments, there are two or moredistinct types of P¹ chain present. In certain embodiments, there areseveral types of P¹ chains present, but at least 80% of the P¹ chainshave one structure with lesser amounts of one or more P¹ chain typesmaking up the remaining 20%.

In certain embodiments, polymer compositions of the present inventioninclude more than 95% chains of type P¹. In other embodiments, polymercompositions of the present invention include more than 97% chains oftype P¹. In certain embodiments, polymer compositions of the presentinvention include more than 99% chains of type P¹.

It should be noted that in certain embodiments, polymer compositions ofthe present invention are characterized in that at least 90% of thechains ends are —OH groups may include mixtures having less than 90%chains of type P¹, as for example when a chain transfer agent capable ofinitiating three or more polymer chains is used. For example, where atriol is used as the chain transfer agent, if 80% of the chains resultfrom initiation by the triol (3-OH end groups per chain) and theremaining 20% of chains have only one —OH end group, the composition asa whole will still contain greater than 90% OH end groups (92.3%).

In certain embodiments, polymer compositions of the present inventioninclude chains of type P¹ derived from diol chain transfer agents. Incertain embodiments, these chains have the formula:

where E and p are as defined above and -A- is an optionally substitutedradical selected from the group consisting of: C₂₋₃₀ aliphatic, C₂₋₃₀heteroaliphatic, 6- to 12-membered aryl, 3- to 12-membered heterocyclic,5- to 12-membered heteroaryl.

In other embodiments, -A- is a polymer selected from the groupconsisting of polyolefins, polyesters, polyethers, polycarbonates,polyoxymethylene and mixtures of two or more of these.

In certain embodiments, polymer compositions of the present inventioninclude chains of type P¹ derived from hydroxy acid chain transferagents. In certain embodiments, these chains have the formula:

where E and p are as defined above and -A- is an optionally substitutedradical selected from the group consisting of: C₂₋₃₀ aliphatic, C₂₋₃₀heteroaliphatic, 6- to 12-membered aryl, 3- to 12-membered heterocyclic,5- to 12-membered heteroaryl.

In certain embodiments, polymer compositions of the present inventioninclude chains of type P¹ derived from diacid chain transfer agents. Incertain embodiments, these chains have the formula:

where E and p are as defined above and -A- is a covalent bond or anoptionally substituted radical selected from the group consisting of:C₂₋₃₀ aliphatic, C₂₋₃₀ heteroaliphatic, 6- to 12-membered aryl, 3- to12-membered heterocyclic, 5- to 12-membered heteroaryl.

In certain embodiments, polymer compositions of the present inventioninclude chains of type P¹ derived from trifunctional chain transferagents. In certain embodiments, these chains have the formula:

where E and p are as defined above each z is independently 0 or 1, and-A- is an optionally substituted radical selected from the groupconsisting of: C₃₋₃₀ aliphatic, C₂₋₃₀ heteroaliphatic, 6- to 12-memberedaryl, 3- to 12-membered heterocyclic, 5- to 12-membered heteroaryl.

In another aspect, the present invention encompasses materials made bycross-linking any of the above polycarbonate polyol polymers. In certainembodiments, such cross-linked materials comprise polyurethanes. Incertain embodiments such polyurethanes encompass thermoplastics, foams,coatings and adhesives.

III. Methods of Making Polycarbonate Polyols

In a third aspect, the present invention encompasses methods forproducing polycarbonate polyols.

In some embodiments, the methods include the steps of: a) providing areaction mixture including one or more epoxides and one or more chaintransfer agents having a plurality of sites capable of supporting thechain growth of CO₂ epoxide copolymers; b) contacting the reactionmixture with a metal complex, the metal complex including a metalcoordination compound having a permanent ligand set and at least oneligand that is a polymerization initiator in the presence of carbondioxide; c) allowing the polymerization reaction to proceed until adesired molecular weight of polymer has been formed; and d) terminatingthe polymerization.

III. a. Epoxides

In some embodiments, the epoxide monomers provided at step (a) includeany of the epoxides described hereinabove with regard to the polymercompositions of matter.

In some embodiments, the epoxide monomers provided at step (a) of theabove-described method have a structure:

-   -   where, R²¹, R²², R²³, and R²⁴, are each independently selected        from the group consisting of: —H; and an optionally substituted        group selected from C₁-₃₀ aliphatic; C₆₋₁₄ aryl; 3- to        12-membered heterocycle, and 5- to 12-membered heteroaryl, where        any two or more of R²¹, R²², R²³,and R²⁴ can be taken together        with intervening atoms to form one or more optionally        substituted 3- to 12-membered rings, optionally containing one        or more heteroatoms.

In certain embodiments, reaction mixtures include one or more epoxidesselected from the group consisting of:

wherein each R^(x) is, independently, selected from optionallysubstituted aliphatic, optionally substituted heteroaliphatic,optionally substituted aryl and optionally substituted heteroaryl.

In certain embodiments, reaction mixtures include ethylene oxide. Inother embodiments, reaction mixtures include propylene oxide. In otherembodiments, reaction mixtures include cyclohexene oxide. In otherembodiments, reaction mixtures include epichlorohydrin. In certainembodiments, reaction mixtures include a glycidyl ether or glycidylester. In certain embodiments, reaction mixtures include phenyl glycidylether. In certain embodiments, reaction mixtures include t-butylglycidyl ether.

In certain embodiments, reaction mixtures include ethylene oxide andpropylene oxide. In certain embodiments, reaction mixtures includepropylene oxide along with from about 0.1 to about 10% of a C₄-C₃₀epoxide. In certain embodiments, reaction mixtures include propyleneoxide along with from about 0.1 to about 10% of a glycidyl ether. Incertain embodiments, reaction mixtures include propylene oxide alongwith from about 0.1 to about 10% of a glycidyl ester. In certainembodiments, reaction mixtures include ethylene oxide along with fromabout 0.1 to about 10% of a glycidyl ether. In certain embodiments,reaction mixtures include ethylene oxide along with from about 0.1 toabout 10% of a glycidyl ester. In certain embodiments, reaction mixturesinclude ethylene oxide along with from about 0.1 to about 10% of aC₄-C₃₀ epoxide.

In certain embodiments, reaction mixtures include epoxides derived fromnaturally occurring materials such as epoxidized resins or oils.Examples of such epoxides include, but are not limited to: EpoxidizedSoybean Oil; Epoxidized Linseed Oil; Epoxidized Octyl Soyate; EpoxidizedPGDO; Methyl Epoxy Soyate; Butyl Epoxy Soyate; Epoxidized Octyl Soyate;Methyl Epoxy Linseedate; Butyl Epoxy Linseedate; and Octyl EpoxyLinseedate. These and similar materials are available commercially fromArkema Inc. under the trade name Vikoflex®. Examples of suchcommerically available Vikoflex® materials include Vikoflex 7170Epoxidized Soybean Oil, Vikoflex 7190 Epoxidized Linseed, Vikoflex 4050Epoxidized Octyl Soyate, Vikoflex 5075 Epoxidized PGDO, Vikoflex 7010Methyl Epoxy Soyate, Vikoflex 7040 Butyl Epoxy Soyate, Vikoflex 7080Epoxidized Octyl Soyate, Vikoflex 9010 Methyl Epoxy Linseedate, Vikoflex9040 Butyl Epoxy Linseedate, and Vikoflex 9080 Octyl Epoxy Linseedate.In certain embodiments, the polycarbonate polyols of the presentinvention incorporate epoxidized fatty acids.

In certain embodiments of the present invention, reaction mixturesinclude epoxides derived from alpha olefins. Examples of such epoxidesinclude, but are not limited to those derived from C₁₀ alpha olefin, C₁₂alpha olefin, C₁₄ alpha olefin, C₁₆ alpha olefin, C₁₈ alpha olefin,C₂₀-C₂₄ alpha olefin, C₂₄-C₂₈ alpha olefin and C₃₀₊ alpha olefins. Theseand similar materials are commercially available from Arkema Inc. underthe trade name Vikolox®. Commerically available Vikolox® materialsinclude those depicted in Table 4, below. In certain embodiments,reaction mixtures including alpha olefins also include other simplerepoxide monomers including, but not limited to: ethylene oxide,propylene oxide, butylene oxide, hexene oxide, cyclopentene oxide andcyclohexene oxide.

III. b. Chain Transfer Agents

In certain embodiments, a chain transfer agent provided in step (a) ofthe above method is any of the chain transfer agents describedhereinabove or mixtures of two or more of these.

In some embodiments, the chain transfer agents provided in step (a) ofthe above methods include one or more polyhydric alcohols. In certainembodiments, a polyhydric alcohol is a diol. In certain embodiments,diols include but are not limited to: 1,2-ethanediol, 1,2-propanediol,1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol,1,5-pentanediol, 2,2-dimethylpropane-1,3-diol,2-butyl-2-ethylpropane-1,3-diol, 1,5-hexanediol, 1,6-hexanediol,1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol,2,2,4,4-tetramethylcyclobutane-1,3-diol, 1,3-cyclopentanediol,1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol,1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol,1,4-cyclohexanedimethanol, and 1,4-cyclohexanediethanol.

Other examples include the polyalkylene glycols such as: diethyleneglycol, triethylene glycol, tetraethylene glycol, higher poly(ethyleneglycol), such as those having number average molecular weights of from220 to about 2000 g/mol, dipropylene glycol, tripropylene glycol, andhigher poly(propylene glycol) such as those having number averagemolecular weights of from 234 to about 2000 g/mol.

In certain embodiments, diol chain transfer agents includehydroxyl-terminated polyolefins. Such materials include polymers sold bySartomer Inc. under the trade name Krasol®. In other embodiments, diolchain transfer agents can include hydroxyl-terminated polyisobutylenes(PIB-diols and -triols) such as Polytail® H or Polytail®HA fromMitsubish Chemical Co. Other examples include hydroxyl-terminatedpolybutadienelstyrene(HTBS).

Yet other examples of suitable diols that may be provided in step (a)include 4,4′-(1-methylethylidene) bis[cyclohexanol],2,2′-methylenebis[phenol], 4,4′-methylenebis[phenol],4,4′-(phenylmethylene)bis[phenol], 4,4′-(diphenylmethylene)bis[phenol],4,4′-(1,2-ethanediyl)bis[phenol], 4,4′-(1,2-cyclohexanediyl)bis[phenol],4,4′-(1,3-cyclohexanediyl)bis[phenol],4,4′-(1,4-cyclohexanediyl)bis[phenol], 4,4′-ethylidenebis[phenol],4,4′-(1-phenylethylidene)bis[phenol], 4,4′-propylidenebis[phenol],4,4′-cyclohexylidenebis[phenol], 4,4′-(1-methylethylidene)bis[phenol],4,4′-(1-methylpropylidene)bis[phenol],4,4′-(1-ethylpropylidene)bis[phenol], 4,4′-cyclohexylidenebis[phenol],4,4′-(2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyldi-2,1-ethanediyl)bis[phenol],1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol,4,4′-[1,3-phenylenebis(1-methylethylidene)]bis[phenol],4,4′-[1,4-phenylenebis(1-methylethylidene)]bis[phenol], phenolphthalein,4,4′-(1-methylidene)bis[2-methylphenol],4,4′-(1-methylethylidene)bis[2-(1-methylethyl)phenol],2,2′-methylenebis[4-methyl-6-(1-methylethyl)phenol],

In certain embodiments, a chain transfer agent provided at step (a) is apolyhydric phenol derivative. In certain embodiments, a polymerizationinitiator is selected from the group consisting of:

In some embodiments, a polyhydric alcohol provided as a chain transferagent in step (a) of the above method is a triol, a tetraol or a higherpolyol. Suitable triols may include, but are not limited to: aliphatictriols having a molecular weight less than 500 such astrimethylolethane; trimethylolpropane; glycerol; 1,2,4-butanetriol;1,2,6-hexanetriol; tris(2-hydroxyethyl)isocyanurate;hexahydro-1,3,5-tris(hydroxyethyl)-s-triazine;6-methylheptane-1,3,5-triol; polypropylene oxide triol; and polyestertriols.

In certain other embodiments, a polyol is a tetraol. Examples ofsuitable tetraols include, but are not limited to: erythritol,pentaerythritol; 2,2′-dihydroxymethyl-1, 3-propanediol; and2,2′-(oxydimethylene) bis-(2-ethyl-1,3-propanediol).

In still other embodiments, a polyol is a carbohydrate. Examples ofsuitable carbohydrates include sugar alcohols, monosaccharides,disaccharides, oligosaccharides and polysaccharides and higher oligomerssuch as starch and starch derivatives.

In some embodiments, one —OH group of a diol is phenolic and the otheris aliphatic. In other embodiments each hydroxy group is phenolic. Incertain embodiments, the chain transfer agent is an optionallysubstituted catechol, resorcinol or hydroquinone derivative.

In some embodiments where a Y-group is —OH, the —OH group is an enoltautomer of a carbonyl group. In some embodiments where a Y group is—OH, the —OH group is a carbonyl hydrate or a hemiacetal.

In certain embodiments, a chain transfer agent provided at step (a)includes a hydroxy acid. In certain embodiments, a chain transfer agentincludes a diacid. In certain embodiments, a chain transfer agentincludes a compound selected from the group consisting of:

In certain embodiments, diacid chain transfer agents include carboxyterminated polyolefin polymers. In certain embodiments, carboxyterminated polyolefins include materials such as NISSO-PB C-seriesresins produced by Nippon Soda Co. Ltd.

In certain embodiments, a provided chain transfer agent is a hydroxyacid. In certain embodiments, a hydroxy acid is selected from the groupconsisting of:

In certain embodiments where the provided chain transfer agent includesan acidic functional group, the compound is provided as a salt. Incertain embodiments a carboxylic chain transfer agent is provided as anammonium salt.

IIIc. Polymerization Catalysts

In some embodiments, a provided metal complex is a polymerizationcatalyst. In certain embodiments, a polymerization catalyst with whichthe reaction mixture is contacted in step (b) of the above-describedmethod include any one or more of the catalysts previously describedherein.

In certain embodiments, the metal complexes of step (b) have the formulaL_(p)-M-(L_(I))_(m), where L_(p) is a permanent ligand set, M is a metalatom, and L_(I) is a ligand that is a polymerization initiator, and m isan integer between 0 and 2, inclusive representing the number ofinitiating ligands present.

In certain embodiments, the metal complexes used in step (b) of themethod have a structure selected from the group consisting of: isselected from the group consisting of:

wherein:

M, R^(c), R′, L_(I), m R^(4a), R^(4a′), R^(5a), R^(5a′), R^(6a),R^(6a′), R^(7a), are as defined above.

In certain embodiments of metal complexes used in step (b), have astructure selected from the group consisting of:

where R^(1a) through R^(7a′) are as defined above.

In certain embodiments of metal complexes used in step (b), have astructure selected from the group consisting of:

where R^(5a), R^(5a′), R^(7a), and R^(7a′) are as defined above. Incertain embodiments, each pair of substituents on the salicaldehydeportions of the complexes above are the same (i.e. R^(5a) & R^(5a′) arethe same and R^(7a) & R^(7a′) are the same). In other embodiments, atleast one of R^(5a) & R^(5a′) or R^(7a) & R^(7a) are different from oneanother.

In certain embodiments, a metal complex used in step (b) of the methodhas formula III:

In certain embodiments, a metal complex used in step (b) of the methodhas formula IV:

In certain embodiments, a metal complex used in step (b) of the methodhas formula V:

wherein:

-   -   R^(c), R^(d), L_(I), m, q, R⁴, R^(4′), R⁵, R^(5′), R⁶, R^(6′),        R⁷, and R^(7′) are as described above, and where [R¹ and R⁴],        [R^(1′) and R^(4′) and any two adjacent R⁴, R^(4′), R⁵, R^(5′),        R⁶, R^(6′), R⁷, and R^(7′) groups can optionally be taken        together with intervening atoms to form one or more rings        optionally substituted with one or more R²⁰ groups.

In certain embodiments, wherein a provided metal complex has formulaIII, R¹, R^(1′), R⁴, R^(4′), R⁶, and R^(6′) are each —H. In certainembodiments, wherein the metal complex has formula III, R⁵, R^(5′), R⁷and R^(7′) are each optionally substituted C₁-C₁₂ aliphatic.

In certain methods wherein a provided metal complex has formula III, R⁴,R^(4′), R⁵, R^(5′), R⁶, R^(6′), R⁷, and R^(7′) are each independentlyselected from the group consisting of: —H,—Si(R¹³)₃;—Si[(CH₂)_(k)R²²]_(z)(R¹³)_((3-z)); methyl, ethyl, n-propyl,i-propyl, n-butyl, sec-butyl, t-butyl, isoamyl, t-amyl, thexyl, trityl,—C(CH₃)Ph₂, —(CH₂)_(p)C[(CH₂)_(p)R²²]_(z)H_((3-z)), andSi(R¹³)_((3-z))[(CH₂)^(k)R²²]_(z), where p is an integer from 0 to 12inclusive and R²² is selected from the group consisting of: aheterocycle; an amine; a guanidine; —N⁻(R¹¹)³X⁻; —P(R¹¹)₃X⁻;—P(R¹¹)_(2 ═N) ⁺═P(R¹¹)₃X⁻;—As⁺(R¹¹)⁻, and optionally substitutedpyridinium.

In certain methods wherein a provided metal complex has formula III, R⁷is selected from the group consisting of —H; methyl; ethyl; n-propyl;i-propyl; n-butyl; sec-butyl; t-butyl; isoamyl; t-amyl; thexyl; andtrityl; and R⁵ is selected from the group consisting of—(CH₂)_(p)CH_((3-z))[(CH₂)_(p)R²²], and—Si(R¹³)_((3-z))[(CH₂)_(k)R²²]_(z).

In certain methods, a provided metal complex has formula IV, R¹, R^(1′),R⁴, R^(4′), R⁶, and R^(6′) are each —H. In certain embodiments, whereina complex is a metallosalenate complex of formula IV, R⁵, R^(5′), R⁷ andR^(7′) are each optionally substituted C₁-C₁₂ aliphatic.

In certain methods wherein a metal complex has formula IV, R⁴, R^(4′),R⁵, R^(5′), R⁶, R^(6′), R⁷, and R^(7′) are each independently selectedfrom the group consisting of: —H,—Si(R¹³)₃;—Si(R¹³)_((3-z))[(CH₂)_(k)R²²]_(z); methyl, ethyl, n-propyl,i-propyl, n-butyl, sec-but butyl, isoamyl, t-amyl, thexyl,trityl,—(CH₂)_(p)C[(CH₂)_(p)R²²]_(z)H_((3-z)),

In certain methods wherein a metal complex has formula IV, R⁷ isselected from the group consisting of —H; methyl; ethyl; n-propyl;i-propyl; n-butyl; sec-butyl; t-butyl; isoamyl; t-amyl; thexyl; andtrityl; and R⁵ is selected from the group consisting of—(CH₂)_(p)CH_((3-z))[(CH₂)_(p)R²²]_(z) and—Si(R¹³)_((3-z))[(CH₂)_(k)R²²]_(z).

In methods wherein a metal complex has formula V, R¹, R^(1′), R⁴,R^(4′), R⁶, and R^(6′) are each —H. In certain embodiments, wherein acomplex is a metallosalenate complex of formula V, R⁵, R^(5′), R⁷ andR^(7′) are each optionally substituted C₁-C₁₂ aliphatic.

In certain methods wherein a metal complex has formula V, R⁴, R^(4′),R⁵, R^(5′), R⁶, R^(6′), R⁷, and R^(7′) are each independently selectedfrom the group consisting of: —H,—Si(R¹³)₃;—Si[(CH₂)_(k)R²¹]_(z)(R¹³)_((3-z)); methyl, ethyl, n-propyl,i-propyl, n-butyl, sec-butyl, t-butyl, isoamyl, t-amyl, thexyl, trityl,—(CH₂)_(p)CH_((3-z))[(CH₂)_(p)R²²]_(z) and—Si(R¹³)_((3-z))[(CH₂)_(k)R²²]_(z).

In certain methods wherein a metal complex has formula V, R⁷ is selectedfrom the group consisting of —H; methyl; ethyl; n-propyl; i-propyl;n-butyl; sec-butyl; t-butyl; isoamyl; t-amyl; thexyl; and trityl; and R⁵is selected from the group consisting of—(CH₂)_(p)CH_((3-z))[(CH₂)_(p)R²²]_(z) and—Si(R¹³)_((3-z))(CH₂)_(k)R²²]_(z).

In some embodiments, a metal complex has a structureL_(p)-M-(L_(I))_(m), where L_(p)-M is selected from the group consistingof:

It is generally desirable to maintain the concentration of a metalcomplex in a polymerization at a low level relative to the epoxide. Incertain embodiments, the molar ratio of metal complex to epoxide rangesfrom about 1:100 to about 1:1,000,000. In certain embodiments, the ratioranges from about 1:5,000 to about 1:500,000. In some embodiments, theratio ranges from about 1:10,000 to about 1:200,000. In otherembodiments, the ratio ranges from about 1:20,000 to about 1:100,000.

III. d. Co-Catalysts

In some embodiments, methods of the present invention include the use ofat least one co-catalyst. In some embodiments, a co-catalyst is presentat step (b). In certain embodiments, a co-catalyst is any one or more ofthe co-catalytic species described above in the description of thepolymerization systems of the present invention. In certain embodiments,a co-catalyst is selected from the group consisting of: amines,guanidines, amidines, phosphines, nitrogen-containing heterocycles,ammonium salts, phosphonium salts, arsonium salts, bisphosphine ammoniumsalts, and a combination of any two or more of the above. In certainembodiments, a co-catalyst is covalently linked to the permanent ligandset of the metal complex.

In embodiments where a method includes a co-catalyst that is an “onium”salt, there is necessarily an anion present to balance the charge of thesalt. In certain embodiments, this is any anion. In certain embodiments,an anion is a nucleophile. In some embodiments, an anion is anucleophile capable of ring-opening an epoxide. In some embodiments, ananion is selected from the group consisting of: azide, halides, alkylsulfonates, carboxylates, alkoxides, and phenolates. In certainembodiments, methods include selected a catalyst and co-catalyst suchthat the initiating ligand on the metal complex and an anion present tobalance the charge of a cationic co-catalyst are the same molecule.

III.e. Reaction Conditions

In certain embodiments, the steps of any of the above methods furthercomprise one or more solvents. In certain other embodiments, thepolymerization steps are performed in neat epoxide without the additionof solvent.

In certain methods, where a polymerization solvent is present, thesolvent is an organic solvent. In certain embodiments, the solvent is ahydrocarbon. In certain embodiments, the solvent is an aromatichydrocarbon. In certain embodiments, the solvent is an aliphatichydrocarbon. In certain embodiments, the solvent is a halogenatedhydrocarbon.

In certain embodiments, the solvent is an ether. In certain embodiments,the solvent is an ester. In certain embodiments the solvent is a ketone.

In certain embodiments suitable solvents include, but are not limitedto: Methylene Chloride, Chloroform, 1,2-Dichloroethane, PropyleneCarbonate, Acetonitrile, Dimethylformamide, N-Methyl-2-pyrrolidone,Dimethyl Sulfoxide, Nitromethane, Caprolactone, 1,4-Dioxane, and1,3-Dioxane.

In certain other embodiments, suitable solvents include, but are notlimited to: Methyl Acetate, Ethyl Acetate, Acetone, Methyl Ethyl Ketone,Propylene Oxide, Tretrahydrofuran, Monoglyme Triglyme, Propionitrile,1-Nitropropane, Cyclohexanone.

In certain embodiments, any of the above methods comprise aliphaticoxide present in amounts concentrations between about 0.5 M to about 20M or the neat concentration of the aliphatic oxide. In certainembodiments, aliphatic oxide is present in amounts between about 0.5 Mto about 2 M. In certain embodiments, aliphatic oxide is present inamounts between about 2 M to about 5 M. In certain embodiments,aliphatic oxide is present in amounts between about 5 M to about 20 M.In certain embodiments, aliphatic oxide is present in an amount of about20 M. In certain embodiments, liquid aliphatic oxide comprises thereaction solvent.

In certain embodiments, CO₂ is present at a pressure of between about 30psi to about 800 psi. In certain embodiments, CO₂ is present at apressure of between about 30 psi to about 500 psi. In certainembodiments, CO₂ is present at a pressure of between about 30 psi toabout 400 psi. In certain embodiments, CO₂ is present at a pressure ofbetween about 30 psi to about 300 psi. In certain embodiments, CO₂ ispresent at a pressure of between about 30 psi to about 200 psi. Incertain embodiments, CO₂ is present at a pressure of between about 30psi to about 100 psi. In certain embodiments, CO₂ is present at apressure of between about 30 psi to about 80 psi. In certainembodiments, CO₂ is present at a pressure of about 30 psi. In certainembodiments, CO₂ is present at a pressure of about 50 psi. In certainembodiments, CO₂ is present at a pressure of about 100 psi. In certainembodiments, the CO₂ is supercritical.

In certain embodiments of the above methods the reaction is conducted ata temperature of between about 0° C. to about 150° C. In certainembodiments, the reaction is conducted at a temperature of between about23° C. to about 100° C. In certain embodiments, the reaction isconducted at a temperature of between about 23° C. and about 80° C. Incertain embodiments, the reaction to be conducted at a temperature ofbetween about 23° C. to about 50° C.

In certain embodiments, a polymerization step of any of the abovemethods produces cyclic carbonate as a by-product in amounts of lessthan about 20%. In certain embodiments, cyclic carbonate is produced asa by-product in amounts of less than about 15%. In certain embodiments,cyclic carbonate is produced as a by-product in amounts of less thanabout 10%. In certain embodiments, cyclic carbonate is produced as aby-product in amounts of less than about 5%. In certain embodiments,cyclic carbonate is produced as a by-product in amounts of less thanabout 1%. In certain embodiments, the reaction does not produce anydetectable by-products (e.g., as detectable by ¹H-NMR and/or liquidchromatography (LC)).

In certain embodiments, a polymerization time is between about 30minutes and about 48 hours. In some embodiments, the reaction is allowedto process for less than 24 hours. In some embodiments, the reaction isallowed to progress for less than 12 hours. In some embodiments, thereaction is allowed to process for between about 4 and about 12 hours.

In certain embodiments, a polymerization reaction is allowed to proceeduntil the number average molecular weight of the polymers formed isbetween about 500 and about 400,000 g/mol. In certain embodiments, thenumber average molecular weight is allowed to reach a value between 500and 40,000 g/mol. In other embodiments, the number average molecularweight is allowed to reach a value between 500 and 20,000 g/mol. Incertain embodiments, the number average molecular weight is allowed toreach a value between 500 and 10,000 g/mol. In other embodiments, thenumber average molecular weight is allowed to reach a value between 500and 5,000 g/mol. In other embodiments, the number average molecularweight is allowed to reach a value between 500 and 2,500 g/mol. In otherembodiments, the number average molecular weight is allowed to reach avalue between 1,000 and 5,000 g/mol.

In certain embodiments, provided methods further include the step ofsampling the reaction and determining the molecular weight of thepolymer at a given time. In certain embodiments, this sampling andmolecular weight determination are performed at two or more timeintervals. In certain embodiments a plot of molecular weight gain overtime is constructed and the method further includes the step ofdetermining from this plot the time at which a desired molecular weightpolymer will be present. In certain embodiments, the time at which thepolymerization is ended is determined by this method.

In certain embodiments, a polymerization reaction proceeds until betweenabout 20% and about 100% of the provided epoxide is consumed. In certainembodiments, the conversion is between about 40% and about 90%. Incertain embodiments, the conversion is at least 50%. In otherembodiments, the conversion is at least 60%, at least 80% or at least85%. In certain embodiments, at least 80% of the provided epoxide isconverted to polymer.

In certain embodiments, a method further includes the step of choosingthe ratios at which the catalyst, the chain transfer agent and theepoxide substrate are provided. In certain embodiments, these ratios areselected to provide high epoxide conversion while providing polyol ofthe desired molecular weight in a selected length of time. In someembodiments, this selection of ratios includes the substeps of: i)selecting a desired length of time for which the reaction is to be run,ii) multiplying the selected length of time for which the polymerizationreaction is to run by the turnover frequency of the catalyst under thereaction conditions iii) multiplying this result by the desired mol%conversion of epoxide, and iv) using the inverse of this result as theratio of catalyst to epoxide used for the reaction. In some embodiments,the ratio of chain transfer agent to catalyst is determined by theadditional following steps; v) taking the value from step (iii) aboveand multiplying this result by the molecular weight of the repeatingunit of the polycarbonate; vi) selecting a desired molecular weight forthe polyol and dividing the result from step (v) by this number; andvii) subtracting the number of chains produced per catalyst moleculefrom the result of step (vi) and taking the result as the ratio of chaintransfer agent to catalyst used in step (1).

To make the steps of the above-described method clear, the followingexample is provided: in a copolymerization of propylene oxide and CO₂using a catalyst that has a TOF of 1000 h⁻¹ and which produces twopolymer chains per catalyst molecule, a polymer with Mn of 2,000 g/molis to be produced and it is desired that 80% of the provided epoxide isconverted during a reaction time of 10 hours, one would perform thefollowing steps to obtain the required ratios:

First, performing taking 10 hours as the selected time interval andperforming step (ii) of multiplying the selected interval of 10 hours,by the TOF of 1000 hr⁻¹ gives 10,000 turnovers per catalyst molecule;next multiplying this number by the desired 80% conversion(step (iii))and then inverting (step (iv)) provides a value of 1.25×10⁻⁴corresponding to a catalyst to epoxide ratio of 1:8,000.

Moving next to determination of the chain transfer agent loading, atstep (iv) one multiplies the result of step (iii) by the molecularweight of the repeating unit of the polycarbonate (in this caseC₄H₆O₃=102 g/mol) and dividing by the desired Mn of 2,000 to give avalue of 408. Subtracting the two chains per catalyst from this resultin a chain transfer to catalyst ratio of 406:1. Therefore, for thisexample the molar ratio of catalyst to epoxide to chain transfer agentshould be approximately 1:8,000:406.

It will be appreciated that the method described above is simplified incertain respects. For example, the calculation described assumes thatthe reaction rate is linear throughout the duration of thepolymerization. The calculation described also dismisses thecontribution that the mass of the chain initiator adds to the molecularweight of the polymer chains. In certain embodiments, particularly thosewhere a polymeric chain transfer agent such as a polyether is used, orwhere a very low molecular weight oligomer is produced, the contributionof the mass of the initiator to the Mn of the polymer may besignificant. It will be understood by those skilled in the art thatadditional chain transfer agent can be added to account for this effect,and more specifically, that the calculations described above can bemodified to account for this effect. Similarly, more detailed kineticdata could be used to account for changes in the reaction rate over timeas the reaction proceeds. For instances where a mixture of epoxides ispresent, the molecular weight of the repeating unit may be approximatedby using a weighted average of the molecular weights of the epoxidespresent in the mixture. This could be further refined by analyzingcopolymer made under similar conditions to determine the mole percentincorporation of the different monomers (for example by using NMRspectroscopy) since all epoxides may not be incorporated into polymerwith equal efficiency. These and other modifications will be readilyapprehended by the skilled artisan and are specifically encompassed bythe methods provided herein.

In certain embodiments, it has been found that the turnover frequency ofsome catalysts decreases as the ratio of chain transfer agent tocatalyst increases. This effect can be particularly noticeable at ratioshigher than about 100:1. In these instances, the above-described methodsmay not produced the expected Mn and monomer conversion in a given timeinterval. In such cases it may be necessary to measure the TOF of thecatalyst at various chain transfer agent ratios prior to performing thecalculations described above. In general, such cases require thereaction interval be lengthened by an amount proportional to the falloffin catalyst activity at the catalyst to chain transfer agent ratio used,or in some embodiments the catalyst loading be increased by acompensatory amount.

As noted above, water present in the reaction mixtures of the describedmethods can also act as a chain transfer agent. In certain embodiments,the calculations described above further include the method of measuringthe water content of the reaction (preferably after the reaction vesselhas been charged with epoxide, chain transfer agent and any solvent tobe used, but prior to addition of the catalyst). The molar equivalentsof water relative to catalyst are then calculated and the ratio of chaintransfer agent to catalyst can be decreased accordingly. If this is notdone and there is significant water present, the Mn will be lower thanexpected at a given % conversion.

IV. Higher Polymers

The present disclosure encompasses higher polymers derived from thepolycarbonate polyols described hereinabove. In certain embodiments,such higher polymers are formed by reacting the polyols with suitablecross-linking agents. In certain embodiments, cross linkers includingfunctional groups reactive toward hydroxyl groups are selected, forexample, from epoxy and isocyanate groups. In certain embodiments, suchcross linking agents are polyisocyanates.

In some embodiments, a difunctional or higher-functionality isocyanateis selected from di-isocyanates, the biurets and cyanurates ofdiisocyanates, and the adducts of diisocyanates to polyols. Suitablediisocyanates have generally from 4 to 22 carbon atoms. Thediisocyanates are typically selected from aliphatic, cycloaliphatic andaromatic diisocyanates, for example 1,4-diisocyanatobutane,1,6-diisocyanatohexane, 1,6-diisocyanato-2,2,4-trimethylhexane,1,6-diisocyanato-2,4,4-trimethylhexane, 1,2-, 1,3- and1,4-diisocyanatocyclohexane, 2,4- and2,6-diisocyanato-l-methylcyclohexane,4,4′-bis(isocyanatocyclohexyl)methane, isophorone diisocyanate(=l-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane), 2,4- and2,6-tolylene diisocyanate, tetramethylene-p-xylylene diisocyanate(=1,4-bis(2-isocyanatoprop-2-yl)benzene),4,4′-diisocyanatodiphenylmethane, preferably 1,6-diisocyanatohexanediisocyanatohexane and isophorone diisocyanate, and mixtures thereof.

In certain embodiments, crosslinking compounds comprise the cyanuratesand biurets of aliphatic diisocyanates. In certain embodiments,crosslinking compounds are the di-isocyanurate and the biuret ofisophorone diisocyanate, and the isocyanate and the biuret of1,6-diisocyanatohexane. Examples of adducts of diisocyanates to polyolsare the adducts of the abovementioned diisocyanates to glycerol,trimethylolethane and trimethylolpropane, for example the adduct oftolylene diisocyanates to trimethylolpropane, or the adducts of1,6-diisocyanatohexane or isophorone diisocyanate to trimethylpropaneand/or glycerol.

In some embodiments, a polyisocyanate used, may, for example, be anaromatic polyisocyanate such as tolylene diisocyanate, diphenylmethanediisocyanate or polymethylene polyphenyl isocyanate, an aliphaticpolyisocyanate such as hexamethylene diisocyanate, xylylenediisocyanate, dicyclohexylmethane diisocyanate, lysine diisocyanate ortetramethylxylylene diisocyanate, an alicyclic polyisocyanate such asisophorone diisocyanate, or a modified product thereof.

In some embodiments, a modified product of a polyisocyanate is aprepolymer modified product which is a reaction product of a lowmolecular weight diol with a low molecular weight triol, a biuretproduct which is a reaction product with water, or a trimer having anisocyanurate skeleton.

The isocyanate group-terminated prepolymer can be produced by reacting astoichiometrically excess amount of a polyisocyanate to the polyolcomposition. It can be produced by thermally reacting the polyolcomposition with the polyisocyanate at a temperature of from 60 to 100°C. for from 1 to 30 hours in a dry nitrogen stream in the presence orabsence of a solvent and optionally in the presence of aurethane-forming catalyst. In some embodiments, a urethane-formingcatalyst is an organometallic compound of tin, lead or titanium. In someembodiments a urethane-forming catalyst is an organic tin compound, suchas dibutyltin dilaurate, dibutyltin dioctoate or stannous octoate.

An isocyanate group-terminated prepolymer of the present invention canbe used for uses known in the art and familiar to the skilled artisan.In some embodiments, it can be used for a humidity curable compositionwhich is cured by a reaction with moisture in air, a two-part curablecomposition to be reacted with a curing agent such as a polyamine, apolyol or a low molecular weight polyol, a casting polyurethaneelastomer, or other applications.

The present invention also provides a polyurethane resin obtained byreacting the above polyol composition with a polyisocyanate. Such apolyurethane resin can be produced by a known method, and a curing agentsuch as a polyamine or a low molecular polyol, or the above mentionedurethane-forming catalyst may optionally be used.

In the production of polyurethanes, polyols of the invention may bereacted with the polyisocyanates using conventional techniques that havebeen fully described in the prior art. Depending upon whether theproduct is to be a homogeneous or microcellular elastomer, a flexible orrigid foam, an adhesive, coating or other form, the reaction mixture maycontain other conventional additives, such as chain-extenders, forexample 1,4-butanediol or hydrazine, catalysts, for example tertiaryamines or tin compounds, surfactants, for example siloxane-oxyalkylenecopolymers, blowing agents, for example water andtrichlorofluoromethane, cross-linking agents, for exampletriethanolamine, fillers, pigments, fire-retardants and the like.

To accelerate the reaction between the isocyanate-reactive groups of thepolyol resin and the isocyanate groups of the crosslinker, it ispossible to use known catalysts, for example, dibutyltin dilaurate,tin(II) octoate, 1,4-diazabicyclo[2.2.2]-octane, or amines such astriethylamine. These are typically used in an amount of from 10⁻⁵ to10⁻² g, based on the weight of the crosslinker.

The crosslinking density can be controlled by varying the functionalityof the polyisocyanate, the molar ratio of the polyisocyanate to thepolyol resin, or by additional use of monofunctional compounds reactivetoward isocyanate groups, such as monohydric alcohols, e.g. ethylhexanolor propylheptanol.

A crosslinker is generally used in an amount which corresponds to anNCO:OH equivalents ratio of from 0.5 to 2, preferably from 0.75 to 1.5and most preferably from 0.8 to 1.2.

Suitable crosslinking agents are also epoxy compounds having at leasttwo epoxide groups in the molecule, and their extension products formedby preliminary extension (prepolymers for epoxy resins, as described,for example in Ullmann's Encyclopedia of Industrial Chemistry, 6thedition, 2000, Electronic Release, in the chapter “Epoxy Resins”). Epoxycompounds having at least two epoxide groups in the molecule include, inparticular:

(i) Polyglycidyl and poly(β-methylglycidyl) esters which are obtainableby reacting a compound having at least two carboxyl groups, such as analiphatic or aromatic polycarboxylic acid, with epichlorohydrin orbeta-methylepichlorohydrin. The reaction is effected, preferably, in thepresence of a base. Suitable aliphatic polycarboxylic acids are oxalicacid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaicacid, dimerized or trimerized linolenic acid, tetrahydrophthalic acid,hexahydrophthalic acid or 4-methylhexahydrophthalic acid. Suitablearomatic polycarboxylic acids are, for example, phthalic acid,isophthalic acid or terephthalic acid.

(ii) Polyglycidyl or poly(β-methylglycidyl) ethers which derive, forexample, from acyclic alcohols, such as ethylene glycol, diethyleneglycol, poly(oxyethylene) glycols, propane-1,2-diol, poly(oxypropylene)glycols, propane-1,3-diol, butane-1,4-diol, poly(oxytetramethylene)glycols, pentane-1,5-diol, hexane-1,6-diol, hexane-2,4,6-triol,glycerol, 1,1,1-trimethylolpropane, pentaerythritol, sorbitol; or cyclicalcohols such as 1,4-cyclohexanedimethanol,bis(4-hydroxycyclohexyl)methane or 2,2-bis(4-hydroxycyclohexyl)propane;or comprise aromatic rings, such as N,N-bis(2-hydroxyethyl)aniline orp,p-bis(2-hydroxyethylamino)diphenylmethane. The glycidyl ethers mayalso derive from monocyclic phenols such as resorcinol or hydroquinone,or polycyclic phenols, such as bis(4-hydroxyphenyl)methane,4,4′-dihydroxybiphenyl, bis(4-hydroxyphenyl)sulfone,1,1,2,2-tetrakis(4-hydroxyphenyl)ethane,2,2-bis(4-hydroxyphenyl)propane,2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, or from novolaks which areobtainable by condensing aldehydes, such as formaldehyde, acetaldehyde,chloral or furfural, with phenols, such as phenol, 4-chlorophenol,2-methylphenol, 4-tert-butylphenol or bisphenols.

(iii) Poly(N-glycidyl) compounds which are obtainable bydehydrochlorinating the reaction products of epichlorohydrin with amineswhich have at least two amine hydrogen atoms, such as aniline,n-butylamine, bis(4-aminophenyl)methane, m-xylylenediamine orbis(4-methylaminophenyl)methane. The poly(N-glycidyl) compounds alsoinclude triglycidyl isocyanurates, N,N′-diglycidyl derivatives ofalkyleneureas such as ethyleneurea or 1,3-propyleneurea, and thediglycidyl derivatives or hydantoins such as 5,5-dimethylhydantoin.

(iv) Poly(S-glycidyl) compounds such as di-S-glycidyl derivatives whichderive from dithiols, such as ethane-1,2-dithiol orbis(4-mercaptomethylphenyl) ether.

(v) Cycloaliphatic epoxy compounds such as bis(2,3-epoxycyclopentyl)ether, 2,3-epoxycyclopentyl glycidyl ether,1,2-bis(2,3-epoxycyclopentyloxy)ethane or 3,4-epoxycyclohexylmethyl3′,4′-epoxycyclohexanecarboxylate; or mixed cycloaliphatic-aliphaticepoxy compounds such as limonene diepoxide.

In some embodiments, the present disclosure encompasses higher polymersformed with polyol resins of the present invention that additionallycomprise a stiffening polymer which comprises (meth)acryloyl and/orvinylaromatic units. The stiffening is obtainable by free-radicallypolymerizing (meth)acrylic monomers or vinylaromatic monomers. Examplesof suitable monomers are styrene, ring-alkylated styrenes withpreferably C₁₋₄ alkyl radicals such as a-methylstyrene, p-methylstyrene,acrylonitrile, methacrylonitrile, acrylamide or methacrylamide, alkylacrylates and methacrylates having from 1 to 4 carbon atoms in the alkylradical, in particular methyl methacrylate. Preference is given to usingmonomers and monomer mixtures which give rise to a polymer or copolymerhaving a glass transition temperature of more than +20° C. andpreferably more than +50° C.

The stiffening polymer may, aside from (meth)acrylic monomers orvinylaromatic monomers, comprise various monomers. The (meth)acrylicmonomers or vinylaromatic monomers make up generally at least 20% byweight, preferably at least 50% by weight, in particular at least 70% byweight, of the constituent monomers.

The encompassed higher polymer compositions may additionally comprisecustomary assistants such as fillers, diluents or stabilizers.

Suitable fillers are, for example, silica, colloidal silica, calciumcarbonate, carbon black, titanium dioxide, mica and the like.

Suitable diluents are, for example, polybutene, liquid polybutadiene,hydrogenated polybutadiene, paraffin oil, naphthenenates, atacticpolypropylene, dialkyl phthalates, reactive diluents, for example,alcohols and oligoisobutenes.

Suitable stabilizers are, for example, 2-benzothiazolyl sulfide,benzothiazole, thiazole, dimethyl acetylenedicarboxylate, diethylacetylenedicarboxylate, BHT, butylhydroxyanisole, vitamin E.

Further higher polymeric materials which may be obtained from thepolyols of the invention include vinyl type polymers made bypolymerising ethylenically unsaturated derivatives of the polyols. Suchderivatives may be obtained, for example, by reacting the polyols withethylenically unsaturated carboxylic acids, for example acrylic,methacrylic and itaconic acids or ester-forming derivatives thereof.

Another useful method of forming ethylenically unsaturated derivativesof the polyols is to react said polyols with organic polyisocyanates,for example those mentioned above, and then to react the isocyanategroup terminated products obtained with hydroxyalkyl acrylates ormethacrylates, for example the 2-hydroxyethyl or 2-hydroxypropylcompounds. Alternatively, the polyols may be reacted withisocyanato-acrylates obtained by reacting a diisocyanate with ahydroxalkyl acrylate or methacrylate.

The ethylenically unsaturated derivatives of the fluorinated polyols maybe polymerized, preferably in the presence of co-monomers such asacrylonitrile, styrene, ethyl acrylate, butyl acrylate or methylmethacrylate, using conditions that have been fully described in theprior art for vinyl polymerisations. Useful molded plastics articles maybe made in this way.

Further higher polymeric materials which may be obtained from thepolyols of the invention include epoxy resins prepared in conventionalmanner from epoxy derivatives of the polyols. Such derivatives may beobtained, for example, by reacting the polyols with epichlorohydrin inthe presence of bases.

Articles of manufacture comprising provided polycarbonate polyol and/orpolyurethane compositions can be made using known methods and proceduresdescribed in the art. The skilled artisan, after reading the presentdisclosure, will be able to manufacture such articles using well knownprotocols and techniques.

EXAMPLES Example 1

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y), and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is 1,    -   each —Y is —OH,    -   -A- is

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III),    -   -L_(I) is a chain transfer agent -Q′-A′(Z)_(n), where Q′ is        COO⁻, -A- is —CH₂—, and Z′ is —OH, and    -   n is 1.

24 mg of catalyst E1 (0.04 mmol), 0.45 g (3.1 mmol)1,4-cyclohexanedimethanol and 20 mg (0.04 mmol) PPN⁺Cl⁻ were held undervacuum in a Fisher-Potter bottle. The bottle was filled with nitrogenand 20 ml propylene oxide was added. The bottle was pressurized with 100psi CO₂. After 41 h at 30° C. the bottle was opened and the polymer wasisolated by pouring into methanol. GPC analysis showed formation of apolymer of M_(n)=4460, M_(w)=4610, PDI=1.035. The polymer has acarbonate content of >97%.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P¹ arising frominitiation by the cyclohexanedimethanol, chains P^(1′) arising frominitiation by the glycolic acid (L_(i)) and chains P² arising from thechloride counterion on the PPN co-catalyst:

where each p is on average approximately 20-21. In this particularcomposition, the ratio of P¹ to P^(1′) to P² is approximately 89:1:1.The polycarbonate polyol composition contains approximately 99% OH endgroups.

Example 2

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is 3,    -   each —Y is —OH,

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

51 mg of catalyst E2 (0.07 mmol), 0.5 g (1.4 mmol) of propoxylatedpentaerythritol and 41 mg (0.08 mmol) PPN⁺Cl⁻were held under vacuum in aFisher-Potter bottle. The bottle was filled with nitrogen and 20 mlpropylene oxide was added. The bottle was pressurized with 100 psi CO₂.After 22 h at 30° C. the bottle was opened and the polymer was isolatedby pouring into methanol. GPC analysis showed formation of a polymerformation of a polymer of M_(n)=13660, M_(w)=15420, PDI=1.129. Thepolymer has a carbonate content of >97%.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P^(1a) arisingfrom initiation by the propoxylated pentaerythritol, chains P^(2a)arising from initiation by the trifluoroacetate (L_(I)) and chains P²arising from the chloride counterion on the PPN co-catalyst:

where each p is on average approximately 30-32. In this particularcomposition, the ratio of P^(1a) to P^(2a) to P² is approximately20:1:1. The polycarbonate polyol composition contains approximately 97%OH end groups.

Example 3

Example 3 was conducted using conditions similar to Example 2, exceptPoly(caprolactone) diol having an Mn of 530 g/mol was used as the chaintransfer agent.

Example 4

Example 4 was conducted using conditions similar to Example 3, exceptPoly(ethylene glycol) having an Mn of 400 g/mol was used as the chaintransfer agent.

Example 5

Example 5 was conducted using conditions similar to Example 3, exceptPoly(propylene glycol) having an Mn of 760 g/mol was used as the chaintransfer agent.

Example 6

Example 6 was conducted using conditions similar to Example 3, except1,2-cyclohexane diol was used as the chain transfer agent.

Example 7

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is 1,    -   each —Y is —OH,    -   -A- is

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

An oven dried glass vessel was charged with 11.5 mg of catalyst E2(0.016 mmol) and 9.2 mg of PPN⁺Cl⁻(0.016 mmol). The vessel was purgedwith nitrogen and 1,4 butane diol (0.073 g, 0.8 mmol) was added as asolution in dry THF (0.5 mL). Propylene oxide (4.5 mL, 64 mmol) was thenadded. The reaction vessel was pressurized with 300 psig dry carbondioxide gas and stirred at 30° C. for 3 hours. The reaction was quenchedwith acid, diluted with 25 mL acetone and concentrated to yield 2.6 g ofcrude polymer. The polymer had an Mn of 4072 g/mol, and a PDI of 1.04.The polymer contained no detectable ether linkages and had greater than98% —OH end groups.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P^(1a) arisingfrom initiation by the 1,4 butanediol, chains P^(2a) arising frominitiation by the trifluoroacetate (L_(I)) and chains P² arising fromthe chloride counterion on the PPN co-catalyst:

where each p is on average approximately 20. In this particularcomposition, the ratio of P^(1a) to P^(2a) to P² is approximately50:1:1.

Example 8

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is 1,    -   each —Y is —OH,    -   -A- is

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

An oven dried glass vessel was charged with 11.5 mg of catalyst E2(0.016 mmol) and 9.2 mg of PPN⁺Cl⁻ (0.016 mmol). The vessel was purgedwith nitrogen and 1,4 propane diol (0.061 g, 0.8 mmol) was added as asolution in dry THF (0.5 mL). Propylene oxide (4.5 mL, 64 mmol) was thenadded. The reaction vessel was pressurized with 300 psig dry carbondioxide gas and stirred at 30° C. for 3× hours. The reaction wasquenched with acid, diluted with 25 mL acetone and concentrated to yield2.7 g of crude polymer. The polymer had an Mn of 4336 g/mol, and a PDIof 1.04. The polymer contained no detectable ether linkages and hadgreater than 98% —OH end groups.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P^(1a) arisingfrom initiation by the 1,3 propanediol, chains P^(2a) arising frominitiation by the trifluoroacetate (L_(I)) and chains P² arising fromthe chloride counterion on the PPN co-catalyst:

where each p is on average approximately 21. In this particularcomposition, the ratio of P^(1a) to P^(2a) to P² is approximately50:1:1.

Example 9

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is 1,    -   each —Y is —OH,    -   -A- is

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

An oven dried glass vessel was charged with 11.5 mg of catalyst E2(0.016 mmol) and 9.2 mg of PPN⁺Cl⁻ (0.016 mmol). The vessel was purgedwith nitrogen and 1,4 butene diol (0.079 g, 0.8 mmol) was added as asolution in dry THF (0.5 mL). Propylene oxide (4.5 mL, 64 mmol) was thenadded. The reaction vessel was pressurized with 300 psig dry carbondioxide gas and stirred at 30° C. for 3 hours. The reaction was quenchedwith acid, diluted with 25 mL acetone and concentrated to yield 1.5 g ofcrude polymer. The polymer had an Mn of 2431 g/mol, and a PDI of 1.06.The polymer contained no detectable ether linkages and had greater than98% —OH end groups.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P^(1a) arisingfrom initiation by the 1,4 butenediol, chains P^(2a) arising frominitiation by the trifluoroacetate (L_(I)) and chains P² arising fromthe chloride counterion on the PPN co-catalyst:

where each p is on average approximately 12. In this particularcomposition, the ratio of P^(1a) to P^(2a) to P² is approximately50:1:1.

Example 10

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is 1,    -   each —Y is —CO₂H,    -   -A- is

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

An oven dried glass vessel was charged with 11.5 mg of catalyst E2(0.016 mmol); 9.2 mg of PPN⁺Cl⁻ (0.016 mmol); succinic acid (0.095 g,0.8 mmol) and 0.5 mL THF. Propylene oxide (4.5 mL, 64 mmol) was thenadded. The reaction vessel was pressurized with 300 psig dry carbondioxide gas and stirred at 30° C. for 3 hours. The reaction was quenchedwith acid, diluted with 25 mL acetone and concentrated to yield 3.0 g ofcrude polymer. The polymer had an Mn of 13,933 g/mol, and a PDI of 1.04.The polymer contained no detectable ether linkages and had greater than98% —OH end groups.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P^(1a) arisingfrom initiation by the succinic acid, chains P^(2a) arising frominitiation by the trifluoroacetate (L_(I)) and chains P² arising fromthe chloride counterion on the PPN co-catalyst:

where each p is on average approximately 68. In this particularcomposition, the ratio of P^(1a) to P^(2a) to P² is approximately50:1:1.

Example 11

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is 1,    -   each —Y is —CO₂H,    -   -A- is

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

An oven dried glass vessel was charged with 11.5 mg of catalyst E2(0.016 mmol); 9.2 mg of PPN⁺Cl⁻ (0.016 mmol); adipic acid (0.12 g, 0.8mmol) and 0.5 mL THF. Propylene oxide (4.5 mL, 64 mmol) was then added.The reaction vessel was pressurized with 300 psig dry carbon dioxide gasand stirred at 30° C. for 3 hours. The reaction was quenched with acid,diluted with 25 mL acetone and concentrated to yield 3.0 g of crudepolymer. The polymer had an Mn of 13,933 g/mol, and a PDI of 1.04. Thepolymer contained no detectable ether linkages and had greater than 98%—OH end groups.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P^(1a) arisingfrom initiation by the adipic acid, chains P^(2a) arising frominitiation by the trifluoroacetate (L_(i)) and chains P² arising fromthe chloride counterion on the PPN co-catalyst:

where each p is on average approximately 68. In this particularcomposition, the ratio of P^(1a) to P^(2a) to P² is approximately50:1:1.

Example 12

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is 1,    -   each —Y is —CO₂H,    -   -A- is

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

An oven dried glass vessel was charged with 11.5 mg of catalyst E2(0.016 mmol); 9.2 mg of PPN⁺Cl⁻(0.016 mmol); terephthalic acid (0.13 g,0.8 mmol) and 0.5 mL THF. Propylene oxide (4.5 mL, 64 mmol) was thenadded. The reaction vessel was pressurized with 300 psig dry carbondioxide gas and stirred at 30° C. for 3 hours. The reaction was quenchedwith acid, diluted with 25 mL acetone and concentrated to yield 1.52 gof crude polymer. The polymer had an Mn of 13,621 g/mol, and a PDI of1.35. The polymer contained no detectable ether linkages and had greaterthan 98% —OH end groups.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P^(1a) arisingfrom initiation by the terephthalic acid, chains P^(2a) arising frominitiation by the trifluoroacetate (L_(I)) and chains P² arising fromthe chloride counterion on the PPN co-catalyst:

where each p is on average approximately 68. In this particularcomposition, the ratio of P^(1a) to P^(2a) to P² is approximately50:1:1.

Example 13

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is 1,    -   each —Y is —CO₂H,    -   -A- is

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

An oven dried glass vessel was charged with 11.5 mg of catalyst E2(0.016 mmol); 9.2 mg of PPN⁺Cl⁻ (0.016 mmol); maleic acid (0.095 g, 0.8mmol) and 0.5 mL THF. Propylene oxide (4.5 mL, 64 mmol) was then added.The reaction vessel was pressurized with 300 psig dry carbon dioxide gasand stirred at 30° C. for 3 hours. The reaction was quenched with acid,diluted with 25 mL acetone and concentrated to yield 3.3 g of crudepolymer. The polymer had an Mn of 5919 g/mol, and a PDI of 1.03. Thepolymer contained no detectable ether linkages and had greater than 98%—OH end groups.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P^(1a) arisingfrom initiation by the succinic acid, chains P^(2a) arising frominitiation by the trifluoroacetate (L_(I)) and chains P² arising fromthe chloride counterion on the PPN co-catalyst:

where each p is on average approximately 29. In this particularcomposition, the ratio of P^(1a) to P^(2a) to P² is approximately50:1:1.

Example 14

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is ,    -   each —Y is —OH,    -   -A- is

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

An oven dried glass vessel was charged with 11.5 mg of catalyst E2(0.016 mmol) and 9.2 mg of PPN⁺Cl⁻ (0.016 mmol). The vessel was purgedwith nitrogen and isosorbide (0.12 g, 0.8 mmol) was added as a solutionin dry THF (0.5 mL). Propylene oxide (4.5 mL, 64 mmol) was then added.The reaction vessel was pressurized with 300 psig dry carbon dioxide gasand stirred at 30° C. for 3 hours. The reaction was quenched with acid,diluted with 25 mL acetone and concentrated to yield 1.53 g of crudepolymer. The polymer had an Mn of 2342 g/mol, and a PDI of 1.05. Thepolymer contained no detectable ether linkages and had greater than 98%—OH end groups.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P^(1a) arisingfrom initiation by the isosorbide, chains P^(2a) arising from initiationby the trifluoroacetate (L_(I)) and chains P² arising from the chloridecounterion on the PPN co-catalyst:

where each p is on average approximately 11.

In this particular composition, the ratio of P^(1a) to P^(2a) to P² isapproximately 50:1:1.

Example 14

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) utilizing a co-catalyst PPN+ Cl—, where

-   -   n is 1,    -   each —Y is —OH,    -   -A- is

where n’ is 10-30 and the avg. MW is 600 g/mol;

-   -   -L_(p) is a salcy ligand

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

An oven dried glass vessel was charged with 11.5 mg of catalyst E2(0.016 mmol); 9.2 mg of PPN⁺Cl⁻ (0.016 mmol); paraformaldehyde (24 mg,0.04 mmol); and dry THF (0.5 mL). Propylene oxide (4.5 mL, 64 mmol) wasthen added. The reaction vessel was pressurized with 300 psig dry carbondioxide gas and stirred at 30° C. for 3 hours. The reaction was quenchedwith acid, diluted with 25 mL acetone and concentrated to yield 1.0 g ofcrude polymer. The polymer had an Mn of 13,262 g/mol, and a PDI of 1.18.

The polycarbonate polyol composition thus obtained consistspredominantly of three types of polymer chains: chains P^(1a) arisingfrom initiation by the isosorbide, chains P^(2a) arising from initiationby the trifluoroacetate (L_(I)) and chains P² arising from the chloridecounterion on the PPN co-catalyst:

where n′ is 10-30 and each p is on average approximately 60.

In this particular composition, the ratio of P^(1a) to P^(2a) to P² isapproximately 2:1:1.

Example 15

This example demonstrates the use of the polymerization system of thepresent invention with a chain transfer agent Y-A-(Y)_(n) and a catalystL_(p)-M-(L_(I))_(m) where,

-   -   n is 1,    -   each —Y is —OH,    -   -A- is

(mixture of isomers);

-   -   -L_(p) is

where each X is trifluoroacetate.

-   -   -M- is Co(III), and    -   -L_(I) is trifluoroacetate.

In a glovebox, catalyst (5.4 mg, 1.0 equiv) was charged to an oven-dried20 mL glass liner. The liner was inserted into a stainless steel highpressure reactor. The system was purged with N₂ five times and purgedwith CO₂ twice. While under the positive flow of CO₂, a solution ofdipropylene glycol (75 μL) in propylene oxide (5 mL, 25,000 equiv) wascharged to the reaction vessel. The reaction was heated to 50° C., thenpressurized with carbon dioxide (300 psi) and stirred.

After 6 h the reaction was vented and quenched with acidic methanol (0.2mL). The reaction was cooled to room temperature, and the resultingpolymer was diluted with acetone (5 mL) and transferred to a foil pan.The unreacted propylene oxide and acetone were removed by evaporation toproduce 2.19 g of an off-white polymer (M_(w)=5,600, M_(w)/M_(n)=1.03.

The polycarbonate polyol composition thus obtained consistspredominantly of two types of polymer chains: chains P¹ arising frominitiation by the dipropylene glycol, and chains P² arising frominitiation by the trifluoroacetate (from L_(I) and X).

where each p is on average approximately 27.

In this particular composition, the ratio of P¹ to P² is approximately4:1.

Other Embodiments

The foregoing has been a description of certain non-limiting embodimentsof the invention. Accordingly, it is to be understood that theembodiments of the invention herein described are merely illustrative ofthe application of the principles of the invention. Reference herein todetails of the illustrated embodiments is not intended to limit thescope of the claims, which themselves recite those features regarded asessential to the invention.

1. A polymerization system for the copolymerization of CO₂ and epoxides,the system comprising: a metal complex having the formulaL_(p)-M-(L_(I))_(m) where L_(p) is a permanent ligand set, M is a metalatom, L_(I) is a ligand that is a polymerization initiator, and m is aninteger between 0 and 2, inclusive representing the number of initiatingligands present; and a chain transfer agent having a plurality of sitescapable of initiating copolymerization of epoxides and CO₂; whereinL_(p)-M has a formula selected from the group consisting of:

wherein: Q, at each occurrence is independently O or S; R¹ and R^(1′)are independently selected from the group consisting of: —H, optionallysubstituted C₁ to C₁₂ aliphatic; optionally substituted 3- to14-membered carbocycle; optionally substituted 3- to 14-memberedheterocycle; and R²¹; R² and R^(2′) are independently selected from thegroup consisting of: —H; optionally substituted C₁ to C₁₂ aliphatic;optionally substituted 3- to 14-membered carbocycle; optionallysubstituted 3- to 14-membered heterocycle; R¹⁴; R²⁰; and R²¹; R³, andR^(3′) are independently selected from the group consisting of: —H;optionally substituted C₁ to C₁₂ aliphatic; optionally substituted 3- to14-membered carbocycle; optionally substituted 3- to 14-memberedheterocycle, and R²¹;

represents an optionally substituted moiety covalently linking twonitrogen atoms, where any of [R^(2′) and R^(3′)], [R² and R³], [R¹ andR²], and [R^(1′) and R^(2′)] may optionally be taken together withintervening atoms to form one or more rings which may in turn besubstituted with one or more groups selected from R¹⁴; R²⁰; and R²¹; andwhere R¹⁴ at each occurrence is independently selected from the groupconsisting of: halogen; optionally substituted C₁ to C₁₂ aliphatic;optionally substituted 3- to 14-membered carbocycle; optionallysubstituted 3- to 14-membered heterocycle; —OR¹⁰; —OC(O)R¹³; —OC(O)OR¹³;—OC(O)NR¹¹R¹²; —CN; —CNO; —C(R¹³)_(z)H_((3-z)); —C(O)R¹³; —C(O)OR¹³;—C(O)NR¹¹R¹²; —NR¹¹R¹²; —NR¹¹C(O)R¹³; —NR¹¹C(O)OR¹³; —NR¹¹SO₂R¹³;—N⁺R¹¹R¹²R¹³X⁻; —P⁺R¹¹)₃X⁻; —P(R¹¹)₃═N⁺═P(R¹¹)₃X⁻; —As⁺R¹¹R¹²R¹³X⁻;—NCO; —N₃; —NO₂; —S(O)_(x)R¹³; and —SO₂NR¹¹R¹², R²⁰ at each occurrenceis independently selected from the group consisting of: halogen; —OR¹⁰;—OC(O)R¹³; —OC(O)OR¹³; —N⁺(R¹¹)₃X⁻; —P⁺(R¹¹)₃X⁻; —P(R¹¹)₃═N⁺═P(R¹¹)₃X⁻;—As⁺R¹¹R¹²R¹³X⁻; —OC(O)NR¹¹R¹²; —CN; —CNO; —C(O)R¹³; —C(O)OR¹³;—C(O)NR¹¹R¹²; —C(R¹³)_(z)H_((3-z)); —NR¹¹R¹²; —NR¹¹C(O)R¹³;—NR¹¹C(O)OR¹³; —NCO; —NR¹¹SO₂R¹³; —S(O)_(x)R¹³; —S(O)₂NR¹¹R¹²; —NO₂;—N₃; and —Si(R¹³)_((3-z))[(CH₂)_(k)R¹⁴]_(z), R²¹ at each occurrence isindependently selected from the group consisting of: —(CH₂)_(k)R²⁰;—(CH₂)_(k)—Z—(CH₂)_(k)R²⁰; —C(R¹⁷)_(z)H_((3-z));—(CH₂)_(k)C(R¹⁷)_(z)H_((3-z));—(CH₂)_(m)—Z—(CH₂)_(m)C(R¹⁷)_(z)H_((3-z)); —(CH₂)_(k)—Z—R¹⁶; X⁻ is anyanion, Z is a divalent linker selected from the group consisting of—(CH═CH)_(a)—; —(CH≡CH)_(a)—; —C(O)—; —C(═NOR¹¹)—; —C(═NNR¹¹R¹²)—; —O—;—OC(O)—; —C(O)O—; —OC(O)O—; —N(R¹¹)—; —N(C(O)R¹³)—; —C(O)NR¹³—;—N(C(O)R¹³)O—; —NR¹³C(O)R¹³N—; —S(O)_(x)—; a polyether; and a polyamine,R¹⁰ at each occurrence is independently selected from the groupconsisting of: —H; optionally substituted C₁-₁₂ aliphatic; an optionallysubstituted 3- to 14-membered carbocycle; an optionally substituted 3-to 14-membered heterocycle —S(O)₂R¹³; —Si(R¹⁵)₃; —C(O)R¹³; and ahydroxyl protecting group, R¹¹ and R¹² at each occurrence areindependently selected from the group consisting of: —H; optionallysubstituted C₁ to C₁₂ aliphatic; an optionally substituted 3- to14-membered carbocycle; an optionally substituted 3- to 14-memberedheterocycle; where two or more R¹¹ or R¹² groups can optionally be takentogether with intervening atoms to form an optionally substituted 3- to10-membered ring, R¹³ at each occurrence is independently selected fromthe group consisting of: —H; optionally substituted C₁ to C₁₂ aliphatic;an optionally substituted 3- to 14-membered carbocycle; and optionallysubstituted 3- to 14-membered heterocycle, where two or more R¹³ groupson the same molecule may optionally be taken together to form ring. R¹⁵at each occurrence is independently selected from the group consistingof: optionally substituted C₁-₁₂ aliphatic, an optionally substituted 3-to 14-membered carbocycle; and an optionally substituted 3- to14-membered heterocycle, a is 1, 2, 3, or 4, k is independently at eachoccurrence an integer from 1 to 8 inclusive, m is 0 or an integer from 1to 8 inclusive, x is 0, 1, or 2, and z is 1, 2, or 3; wherein the chaintransfer agent has a structure Y-A-(Y)_(n), where: each —Y group isindependently a functional group capable of initiating chain growth ofepoxide CO₂ copolymers and each Y group may be the same or different;-A- is a covalent bond or a multivalent moiety; and n is an integerbetween 1 and 10, inclusive. 2-66. (canceled)
 67. A method for thesynthesis of aliphatic polycarbonate polyols having a high percentage of—OH end groups, the method comprising the steps of: a) contacting areaction mixture comprising one or more epoxides with a polymerizationsystem of claim 1 in the presence of carbon dioxide, wherein the molarratio of metal complex to epoxide ranges from about 1:100 to about1:1,000,000; b) allowing the polymerization reaction to proceed until adesired molecular weight aliphatic polycarbonate polyol has formed,wherein in the aliphatic polycarbonate polyol composition, at least 90%of the end groups are hydroxyl groups; and c) terminating thepolymerization. 68-94. (canceled)
 95. A polycarbonate polyol compositioncomprising an epoxide CO₂ copolymer characterized in that the copolymerhas: an Mn between about 400 and about 20,000, greater than 90%carbonate linkages, and at least 90% of the end groups are hydroxylgroups.
 96. (canceled)
 97. The polycarbonate polyol composition of claim95, comprising greater than 95% carbonate linkages. 98-99. (canceled)100. The polycarbonate polyol composition of claim 95, having an Mnbetween about 500 and about 5,000 g/mol. 101-106. (canceled)
 107. Thepolycarbonate polyol composition of claim 95 comprising polymer chainsdenoted P¹ having the formula T-Y-A-(Y-T)_(n) wherein: each -T is apolycarbonate chain having a formula independently selected from thegroup consisting of:

wherein: E is an optionally substituted C₂ unit derived from an epoxide,where E may represent a monomer unit derived from one type of epoxide,or a mixture of two or more types of epoxide, and p ranges from about 5to about 10,000 each —Y group is independently a functional groupcapable of initiating chain growth of epoxide CO₂ copolymers and each Ygroup may be the same or different, -A- is a covalent bond or amultivalent moiety; and n is an integer between 1 and 10 inclusive. 108.The polycarbonate polyol composition of claim 107, further comprisingpolymer chains denoted P² having a formula selected from the groupconsisting of:

wherein X is a bound form of an anion capable of initiating only onepolymer chain. 109-112. (canceled)
 113. The polycarbonate polyolcomposition of claim 107, further comprising polymer chains denotedP^(1a) having a formula:


114. (canceled)
 115. The polycarbonate polyol composition of claim 107,wherein each E is

where, R²¹, R²², R²³, and R²⁴, are each independently selected from thegroup consisting of: —H; and an optionally substituted group selectedfrom C₁-₃₀ aliphatic; C₆₋₁₄ aryl; 3- to 12-membered heterocycle, and 5-to 12-membered heteroaryl, where any two or more of R²¹, R²², R²³, andR²⁴ can be taken together with intervening atoms to form one or moreoptionally substituted 3- to 12-membered rings, optionally containingone or more heteroatoms.
 116. (canceled)
 117. The polycarbonate polyolcomposition of claim 115, wherein -E- comprises predominantly —CH₂CH₂—units derived from ethylene oxide, or wherein -E- comprisespredominantly —CH₂CH(CH₃)— groups derived from propylene oxide. 118-124.(canceled)
 125. The polycarbonate polyol composition of claim 107, wherechains of type P¹ have the formula:

126-130. (canceled)
 131. A polyurethane composition formed by reactionof one or more isocyanates with an aliphatic polycarbonate polyol ofclaim
 95. 132. An article of manufacture comprising an aliphaticpolycarbonate polyol composition of claim
 95. 133. (canceled)
 134. Thepolyurethane composition of claim 131, wherein the composition comprisesa foam or coating.
 135. The polycarbonate polyol composition of claim107, wherein at least 95% of the end groups of the polycarbonate polyolare OH groups.
 136. The polycarbonate polyol composition of claim 107,wherein at least 99% of the end groups of the polycarbonate polyol areOH groups.
 137. The polycarbonate polyol composition of claim 107,wherein the PDI of the polycarbonate polyol is less than 1.6.
 138. Thepolycarbonate polyol composition of claim 107, wherein the PDI of thepolycarbonate polyol is less than 1.2.
 139. The polycarbonate polyolcomposition of claim 107, wherein the Y-A-(Y)_(n) moiety is derived froma chain transfer agent selected from a polyhydric alcohol, apolycarboxylic acid, or a hydroxy acid.
 140. The polycarbonate polyolcomposition of claim 107, wherein the Y-A-(Y)_(n) moiety is derived froma chain transfer agent, wherein at least one Y group is a carboxylicacid and one or more additional Y groups are —OH.